Chapter 4 RQ
On the autumnal equinox the sun rises
Due east
The eerie and pretty northern and southern lights that are produced when gases in Earth's upper atmosphere glow from energy delivered by the solar wind are referred to as
Aurorae
In the context of granulation, convection occurs when hot fluid sins and cool fluid rises
False
Spiral arms are concentrated at the center of our Galaxy (T or F)
False
Sunspots are hot spots on the Sun's surface caused by weak magnetic fields
False
Earth is an example of a Jovian planet?
false
The Very Long Baseline Interferometer (VLBI)
is a set of radio telescopes linked together electronically to provide very high resolution.
T/f light can behave as a particle or as a wave
true
When the weight of a spinning top, which causes it to tip over, combines with the top's rapid rotation and makes its axis sweep out the shape of a cone, that motion is known as _____. precession revolution eccentricity conjunction
Precession
Earths ___ atmosphere had zero free oxygen
Primary
are massive objects destined to become planets.
Protoplanets
is the nearest star to the Sun
Proxima Centauri
Who propsed the idea of epicycles to the geocentric model of the universe?
Ptolemy
Which of the following ancient astronomers believed in the geocentric model of the universe? Ptolemy Aristotle Copernicus
Ptolemy and Aristotle
is that component of an object's velocity that is directed away from or toward an observer.
Radial velocity
Which of the following types of electromagnetic radiation has the smallest frequency
Radio
Which of the following types of electromagnetic radiation has the smallest frequency?
Radio
In the context of the electromagnetic spectrum, which of the following types of electromagnetic radiation has the longest wavelength?
Radio waves
Among the following electromagnetic waves, photons of which electromagnetic radiations carry the lowest energy? Radio waves Visible light Gamma rays Ultraviolet
Radio waves Correct. The amount of energy a photon carries depends on its wavelength. Shorter-wavelength photons carry more energy, and longer-wavelength photons carry less energy. Radio waves have the longest wavelengths among the rest of the electromagnetic radiation; therefore, the photons of radio waves carry less energy than any other electromagnetic radiation.
Which of the following statements is true in the context of visible light spectrum?
Red light has the longest wavelength that can be seen by the average human eye.
Which of the following statements is true in the context of visible light spectrum? Red light has the longest wavelength that can be seen by the average human eye. Red light has more energy than blue light. Red light has a higher frequency than blue light. Red light has the shortest wavelength that can be seen by the average human eye.
Red light has the longest wavelength that can be seen by the average human eye.
In the context of blackbody radiation, which of the following statements is true of stars?
Red stars are cool, and blue stars are hot.
Which of the following statements is true of stars
Red stars are cool, blue are hot
A _____ has a main mirror called the primary mirror
Reflecting telescope
modern optical telescopes
Reflecting telescopes with standard designs depicted on this page have capabilities limited by complexity, weight, and the turbulence in Earth's atmosphere. Modern design solutions are shown on the opposite page. The primary mirror makes light converge to a prime focus position high in the telescope tube, as shown at the right . Although the prime focus is a good place to image faint objects, it is inconvenient for large instruments. A secondary mirror can reflect the light through a hole in the primary mirror to a Cassegrain focus. This focal arrangement is the most common one for large telescopes. Icon Smaller telescopes are often built with a Newtonian focus, the arrangement that Isaac Newton used in his first reflecting telescope. The Newtonian focus is inconvenient for large telescopes, as shown at right. Icon Many small telescopes such as the one on the left use a Schmidt-Cassegrain focus. A thin correcting plate improves the image but is not curved enough to introduce serious chromatic aberration. Icon Shown below, observations using the Mayall Telescope at Kitt Peak National Observatory in Arizona can be made at either the prime focus or the Cassegrain focus. Note the human figure at lower right. Icon Telescope mountings must contain a sidereal drive to move the telescope smoothly westward, countering the eastward rotation of Earth. The earlier equatorial mount (far left) has a polar axis parallel to Earth's axis, but the mount used for the largest modern telescopes is alt-azimuth mount (altitude-azimuth; near left) moves like a cannon—up and down, left and right. Alt-azimuth mountings are simpler to build than equatorial mountings but require computer control to follow the stars. Icon Unlike traditional thick mirrors, thin mirrors, sometimes called "floppy" mirrors as shown at right, weigh less and require less massive support structures. Also, they cool rapidly at nightfall, and there is less distortion from uneven expansion and contraction. Icon Grinding a large mirror may remove tons of glass and take months, but new techniques speed the process. Some large mirrors are cast in a rotating oven that causes the molten glass to flow to form a concave upper surface. Grinding and polishing such a preformed mirror is much less time consuming. Icon Mirrors made of segments are economical because the segments can be made separately. The resulting mirror weighs less and cools rapidly. Icon Both floppy mirrors and segmented mirrors sag under their own weight. Their optical shapes must be controlled by computer-driven thrusters behind the mirrors, a technique called active optics. Icon The two Keck telescopes, each meters in diameter, are located atop the extinct volcano Mauna Kea in Hawai'i. Their two primary mirrors are composed of hexagonal mirror segments, as shown at right . - With large enough telescopes, astronomers can actually ride inside a prime-focus "cage," although observations are usually made using instruments connected to computers in a separate control room.
compare and contrast reflecting/refracting telescopes
Reflecting telescopes: 1) Use a mirror to gather/ focus light 2) main mirror called the "primary mirror" Refracting telescopes: 1) Use a lens to gather/focus light 2) Main lens is called a primary lens Both: 1) form an image that is small, inverted, and difficult to observe directly, so a lens called the eyepiece normally is used to magnify the image and make it convenient to view.
____ refers to the ability of a telescope to reveal fine detail.
Resolving power
refers to the ability of a telescope to reveal fine detail.
Resolving power
_____ refers to the ability of a telescope to reveal fine detail. Focal length Magnifying power Spherical aberration Resolving power
Resolving power Correct. Resolving power refers to the ability of a telescope to reveal fine detail. All else being equal, telescopes with larger diameter primary mirrors have better resolving power. As radio telescopes measure longer wavelengths, they have less resolving power than optical telescopes of the same size.
The occasional backward motion of the planets against the background of fixed stars is called _____. oscillation retrograde motion anterograde motion rotation
Retrograde Motion
Is the volume of space a star controls gravitationally within a binary system
Roche Lobes
_____ is the motion around an axis passing through the spinning body. Rotation Projection Revolution Precession
Rotation
is the motion around an axis passing through the spinning body
Rotation
Venus has an incredibly thick atmosphere containing carbon dioxide. This planet is considered to have a(n) ___ greenhosue effect
Runaway
Sun, Earth, and Moon during neap tides
S- M -E (moon is first or third quarter above earth & neap tides are vertical rings around the Earth)
Sun, Earth, and Moon during a Solar Eclipse
S-M-E
Sun, Earth, and Moon during spring tides
S-M-E (moon is new or full& spring tides are horizontal rings around the Earth)
Atmosphere Density Fluctuates
SEPT 20
The early astronomers imagined that the entire Universe was enclosed inside the celestial sphere that lay just beyond the planet _____. Saturn Mars Uranus Jupiter
Saturn
The rings of ___ are easily visible from Earth
Saturn
Which of the following is a planet that is visible to the naked eye from Earth?
Saturn
Which of the following is a planet that is visible to the naked eye from Earth? Neptune Uranus Saturn Keplar 10b
Saturn
______ Is a method for expressing very large or very small numbers by using powers of 10
Scientific notation
The atmosphere you breathe today is Earth's ____ atmosphere
Secondary
Which of the following statements is true of white dwarfs...
Some are among the hottest known stars
Issac Newton concluded that a force from Earth had to act on the Moon because
Some force is needed to accelerate the Moon toward Earth
Which of the following statements is true of white dwarfs?
Some of them are among the hottest stars known.
Asteroids are examples of
Space debris
A _____ is a device that separates light by wavelength to produce a spectrum
Spectrograph
In which way does a photon of blue light NOT differ from a photon of red light?
Speed
The light gathering power of a telescope is directly proportional to the
Square of the diameter of the primary mirror or lense
Apparent visual magnitudes
Star brightness expressed in the magnitude system are known as ______, describing how the stars look to human eyes observing from Earth.
If you take a photograph of a nearby star and after 6 months take another photograph of the star from a lighty different location in space, you would observe that the
Star is not in exactly the same place in the two photographs
The H-R diagram can help you understand different kinds of
Stars
Sun, Earth, and Moon during a Lunar Eclipse
Sun-Earth-Moon
Solar System Order
Sun-Mercury-Venus-Earth-Mars-Astroid Belt-Jupiter-Saturn-Uranus-Neptune-Kuiper Belt
In the Ptolemaic model, Mercury and Venus had to be treated differently from the rest of the planets: Their epicycles had to remain centered on the Earth-Sun line. T/F
T
In the context of the Sun's surface glowing when hot, yellow-hot is hotter than red-hot but not as hot as white-hot. T/F
T
Radio astronomers face a problem of radio interference analogous to light pollution. T/F
T
Spiral arms help in star formation. T/F
T
Two bodies revolve around their common center of mass, the balance point of the system. T/F
T
To adjust the speed of a planet, Ptolemy supposed that Earth was slightly off center and that the center of the epicycle moved such that it appeared to move at a constant rate as seen from a point called the equant (T or F)
TRUE
Comets are known for their
Tails
Triangulation
Technique astronomers use to calculate the distance to a specific star
Which of the following is not a type of binary star system? Visual Binary Eclipsing Binary Telescopic Binary Spectroscopic Binary
Telescopic Binary
is a measure of the agitation among the atoms and molecules of a material
Tempature
The set of star types, called the spectral sequence, is important because it is a
Temperature sequence
Olympus Mons is directly next to
Tharsis Volcanoes
is one of the gaps in the rings of Saturn that are caused by resonances with moons.
The Cassini Division
is an apparent change in the wavelength of radiation caused by relative motion of a source and observer.
The Doppler effect
West Virginia
The largest fully steerable radio telescope is in _____.
largest radio dish
The largest single radio dish in the world at the time of this writing (mid-2014) is m in diameter. Such a large dish can't be supported easily, so it is built into a mountain valley in Arecibo, Puerto Rico. The primary mirror is a thin metallic surface supported above the valley floor by cables attached near the rim, and the antenna platform hangs above the dish on cables from towers built on three mountain peaks around the valley's rim (Figure 6-17). By moving the antenna above the dish, radio astronomers can point the telescope at any object that passes within degrees of the zenith as Earth rotates
says that the amount of energy flowing out of the top of a layer in the star must be equal to the amount of energy coming in at the bottom, plus whatever energy is generated within the layer.
The law of conversation of energy
_____ says that the total mass of a star must equal the sum of the masses of its shells.
The law of conversation of mass
_____ says that energy must flow from hot regions to cooler regions either by conduction, convection, or radiation.
The law of energy transport
Magnifying power
The least important power of a telescope is _____.
is a unit of distance equal to the distance light travels in 1 year
The light-year
700 nanometers
The longest wavelength of visible light is _____.
Ground state
The lowest energy level an electron can occupy is called the ____.
primary lens
The main lens in a refracting telescope.
Which if the following is true of the moon orbiting Earth
The moon orbits eastward around Earth once a month
The heavens
The most perfect region according to Aristotle's philosophy.
Which of the following was discovered by Galileo Galilei? The other galaxies in the Universe The mountains and valleys on the surface of the Moon The planets Uranus and Neptune The planets being in elliptical motion around the Sun
The mountains and valleys on the surface of the Moon
Which of the following was discovered by Galileo Galilei? The mountains and valleys on the surface of the Moon The other galaxies in the Universe The planets Uranus and Neptune The planets being in elliptical motion around the Sun
The mountains and valleys on the surface of the Moon Correct. Galileo Galilei discovered that the Moon was not perfect. It had mountains and valleys on its surface, and Galileo used the shadows to calculate the height of the mountains.
retrograde motion
The occasional backward motion of the planets against the background of fixed stars is called
Retrograde motion
The occasional backward motion of the planets against the background of fixed stars is called _____.
Retrograde motion
The occasional backwards motion of the planets against the background of fixed stars is
mass
The of an objects is a measure of the amount of matter in the object.
In the context of the Sun's surface, which of the following is the source of most of the sunlight received by Earth?
The photosphere
In the context of the Sun's surface, which of the following is the source of most of the sunlight received by Earth? The photosphere The convection zone The chromosphere The corona
The photosphere
In the context of the Sun's surface, which of the following is the source of most of the sunlight received by Earth? The convection zone The chromosphere The Corona The Photosphere
The photosphere
In the context of the sun surface which of the following is a source of most of the sunlight received by earth
The photosphere
Keller's first law of planetary motion implies that
The planets move in elliptical orbits around the sun
Penumbra
The portion of a shadow that is only partially shaded.
26,000 years
The precession of Earth's axis takes about _____ for one cycle.
Copernican Revolution
The problem of the place of Earth was resolved by the ______.
Umbra
The region of a shadow that is totally shaded is known as the
Umbra
The region of a shadow that is totally shaded is known as the ______.
Latin or Greek
The scientific names of constellations are written in _____.
In Keplers 3rd law the distance between the sun and a planet is equivalent to
The semi major axis of the planets orbit
400 nanometers
The shortest wavelength of visible light is _____.
Which of the following is true of early astronomers?
The thought the entire Universe consisted of Earth, the Sun, the Moon, and the five other planets
Sidereal period
The time taken by the Moon to circle the sky once and return to the same position among the star is known as the Moon's _____.
OSidereal period
The time taken by the Moon to circle the sky once and return to the same position among the stars is known as the Moon's
Precession
The twisting of the axis of rotation combined with the rotation of an object causes _____.
Which of the following statements is true of the analysis called helioseismology?
The vibrations in the Sun are used by solar astronomers to explore its depths
Which of the following statements is true of the analysis called helioseismology?
The vibrations in the Sun are used by solar astronomers to explore its depths.
_____ is the location in the H-R diagram where stars first reach stability as hydrogen-burning stars.
The zero-age sequence
What do all stars on the main sequence have in common?
They are all burning hydrogen into helium in their cores
Which of the following is true of the scientific names of constellations?
They are in Latin or Greek
Which of the following is true of the scientific names of constellations? They are in Latin or Greek. They are in French or Italian. They are in Sumerian or Mayan. They are in Hebrew or Arabic.
They are in Latin or Greek
Which of the following is true of stony meteorites? They are mainly composed of nickel. They are a type of achondrite. They are silicate masses. They are mainly composed of iron.
They are silicate masses
Which of the following is true of stony meteorites?
They are silicate masses.
Which of the following is true of asteroids? They are small rocky worlds They are small icy bodies Most of them orbit between the orbits of Mercury and Venus Most of them are the size of Earth
They are small rocky worlds
Which of the following is true of first-magnitude stars?
They are the stars with the greatest flux.
Which of the following is true of ancient astronomers
They believed that the sky was a great sphere surrounding Earth
Which of the following statements is true of stars?
They die when they exhaust their fuel, allowing gravity to take control.
Which of the following statements is true regarding the stars in a stellar association?
They drift away from each other in a few million years.
Which of the following statements is true of giant stars?
They have more surface area than main-sequence stars of the same temperature
Which of the following statements is true of type I supernovae?
They have no hydrogen lines in their spectra.
Which of the following is true of spring tides? They occur at dawn and dusk every day. They occur at noon and midnight every day. They occur at new moon and full moon. They occur at first- and third-quarter moons.
They occur at new moon and full moon.
Which of the following is true of early astronomers? They knew that the planets were made of rock and gas, much like Earth. They thought that stars were other objects like the Sun and that we lived inside a galaxy. They thought the entire Universe consisted of Earth, the Sun, the Moon, and five other planets. They knew that there were many other galaxies in the Universe.
They thought the entire Universe consisted of Earth, the Sun, the Moon, and five other planets.
Which of the following is true of P waves?
They travel like sound waves.
Ecliptic
Through the year, the Sun moves eastward among the stars following a line called the _____, the apparent path of the Sun among the stars.
the largest of Saturn's moons, has an atmosphere composed mostly of nitrogen with traces of argon and methane.
Titan
inertia
To move (or stop) an object requires a force and that force is proportional to "mass"
A lunar eclipse that occurs when the Moon moves completely into Earth's umbral shadow is called a _____. total lunar eclipse total solar eclipse penumbral lunar eclipse partial solar eclipse
Total Lunar Eclipse
If the orbit of the Moon carries it through the umbra of Earth's shadow, you see a__________. partial lunar eclipse partial solar eclipse total lunar eclipse total solar eclipse
Total lunar eclipse
__________refer to rare occasions when Venus can be seen as a tiny dot directly between Earth and the Sun. Solar phenomena of Venus Transits of Venus Meteors of Venus Light pillars of Venus
Transits of Venus
refer to rare occasions when Venus can be seen as a tony dot direction between Earth and the Sun
Transits of Venus
refers to rare occasions when venus can be seen as a tiny dot directly between Earth and the Sun
Transits of Venus
An intrinsically very bright stars might appear faint if it is far away
True
Ancient astronomers believed that Earth did not move because they saw no parallax
True
Ancient astronomers believed that Earth did not move because they saw no parallax (T or F)
True
As the moon grows fatter from new to full, it is said to wax (T or F)
True
As the moon grows fatter from new to full, it is said to wax t or f
True
In a reflecting telescope, the objective is a mirror.
True
In the Ptolemaic model, Mercury and Venus had to be treated differently from the rest of the planets. Their epicycles had to remain centered on the Earth-Sun line
True
In the Ptolemaic model, Mercury and Venus had to be treated differently from the rest of the planets: Their epicycles had to remain centered on the Earth-Sun line. (T or F)
True
Issac Newton guessed that gravity works by an inverse square relation because he had already discovered that light behaves this way
True
LIght pollution makes it impossible to see faint objects
True
Light can behave as a particle or as a wave.
True
One of the advantages of charge-coupled devices over photographic plates is that a CCD can record bright and faint objects on the same exposure.
True
The amount of energy a photon carries depends on its wavelength.
True
The light-gathering power of a telescope increases as the size of the objective increases.
True
The seasons result from the tip of the Earth's equator and axis relative to its orbit
True
To adjust the speed of a planet, Ptolemy supposed that Earth was slightly off center and that the center of the epicycle moved such that it appeared to move at a constant rate as seen from a point called the equant
True
Venus is visible in the west after sunset or in the east before sunrise (T or F)
True
Precession
When the weight of a spinning top, which causes it to tip over, combines with the top's rapid rotation and makes its axis sweep out the shape of a cone, that motion is known as
coincides with the period called the "Little Ice Age," a time of unusually cool weather in Europe and North America.
The Maunder minimum
is the hazy band of light that circles our sky, produced by the glow of our galaxy
The Milky Way
Which of the following is true of the Moon orbiting Earth?
The Moon orbits eastward around Earth once a month
_______ is an 18 year, 11 day period after which the pattern of lunar and solar eclipses repeats
The Saros cycle
Which if the following stars is part of the Solar System?
The Sun
Which of the following is an example of a star?
The Sun
Which of the following stars is part of the solar system?
The Sun
Vernal Equinox
The Sun crosses the celestial equator going northward at the point called the ______.
Autumnal Equinox
The Sun crosses the celestial equator going southward at the point called the ______.
Winter Solstice
The Sun reaches its most southern point at the ______.
Celestial sphere
The _____ is an imaginary sphere of very large radius surrounding Earth to which the planets, stars, Sun and Moon seem to be attached.
Mass
The _____ of an object is a measure of the amount of matter in the object.
Zodiac
The ______ is a band centered on the ecliptic and encircled the sky.
Zenith
The ______ marks the top of the sky above your head.
Which of the following statements is true of a Doppler shift? A light source approaching an observer will appear red. A light source moving away from an observer will appear blue. The shift in the velocity of the source is identified irrespective of its direction. The amount of change in wavelength depends on the speed of the source.
The amount of change in wavelength depends on the speed of the source.
the atmosphere & how it affects what we can see
The atmosphere produces background light which limits how faint stars we can see. Human light pollution also contributes to the background.
Which of the following is a reason why the Ptolemaic model was the accepted model of the Universe? The authority of Aristotle was immense. It proved that the Sun was at the center of the Universe. It was a very good predictor of planet positions. The multiple revisions to the model made it completely accurate.
The authority of Aristotle was immense. Correct. In spite of many revisions, the Ptolemaic model was still a poor predictor of planet positions, but because of the authority of Aristotle, it was the almost universally accepted model.
Which of the following lies halfway between the celestial poles?
The celestial equator
Mare
The dark areas that are smooth lowlands on Eart's moon is called
why you can't measure the diameters of stars by looking at them through a telescope
The diameter of the images in the telescope is set by diffraction and not by the actual diameters of the stars. That is, the stars are much smaller in diameter than the diameter of the diffraction images.
Which of the following features of a telescope determines its light gathering power?
The diameter of the objective
Which of the following features of a telescope determines its light gathering power?
The diameter of the primary mirror
____ is the site of most of the star formation in the Milky Way galaxy
The disk component
wavelength
The distance between successive peaks or troughs of a wave; usually represented by
Saturn
The early astronomers imagined that the entire Universe was enclosed inside the celestial sphere that lay just beyond the planet
Saturn
The early astronomers imagined that the entire Universe was enclosed inside the celestial sphere that lay just beyond the planet.
Aurorae
The eerie and pretty northern and southern lights that are produced when gases in Earth's upper atmosphere glow from energy delivered by the solar wind are referred to as ____.
is inversely proportional to the wavelength of the light.
The energy of a photon:
O Solar Eclipse
The event that occurs when the Moon passes directly between the Earth and the Sun.
large gamma ray space telescope
The first large gamma-ray space telescope was the Compton Gamma Ray Observatory, launched in 1991. It mapped the entire sky at gamma-ray wavelengths. The European-built INTernational Gamma-Ray Astrophysics Laboratory (INTEGRAL) satellite was launched in 2002 and has been very productive in the study of violent eruptions of stars and black holes. The Fermi Gamma-ray Space Telescope, launched in 2008 and operated by a consortium of nations led by the United States, is capable of making highly sensitive gamma-ray maps of large areas of the sky. Modern astronomy has come to depend on observations that cover the entire electromagnetic spectrum. More orbiting space telescopes are planned that will be even more versatile and sensitive than the ones operating now.
modern telescopes
The four telescopes of the European Very Large Telescope (VLT) are housed in separate domes at Paranal Observatory in Chile. (b) The Large Binocular Telescope (LBT) in Arizona carries two -m mirrors. The light gathered by the two mirrors can be analyzed separately or combined. The entire building rotates as the telescope moves. (c) The Gran Telescopio Canarias (GTC) on La Palma in the Canary Islands contains hexagonal mirror segments in its -m primary mirror. - Other giant telescopes are being planned for completion in the 2020s, all with segmented or multiple mirrors (Figure 6-15). The Giant Magellan Telescope (GMT) will carry seven asymmetrically curved thin mirrors, each m in diameter, on a single mounting. It will be located in Chile and have the light-gathering power of a single -m telescope. The Thirty Meter Telescope (TMT), now under development by a consortium of countries, including the United States, Canada, Japan, China, and India, is planned to have a mirror up to m in diameter comprised of hexagonal segments and will be placed on Mauna Kea in Hawai'i. An international team is designing the European Extremely Large Telescope (E-ELT) to carry segments, making up a mirror m (nearly ft) in diameter. The E-ELT will be built on Cerro Armazones, a mountain in Chile's Atacama Desert.
Milky Way
The hazy band of light that circles our sky.
Which of the following was the most perfect region according to Aristotle's philosophy?
The heavens
Which of the following was the most perfect region according to Aristotle's philosophy? The center of the Sun Earth's center The heavens Earth's surface
The heavens
The Sun reaches its most southern point at the _____. winter solstice vernal equinox summer solstice autumnal equinox
Winter Solstice
are electromagnetic waves with wavelength shorter than ultraviolet (UV) light.
X-rays
What is the name for a post-main sequence star whose cor has fusion occurring?
Yellow Giant
adaptive objects
You have already learned about active optics, which is a technique to adjust the shape of telescope optics slowly, compensating for effects of changing temperature as well as gravity bending the mirror when the telescope points at different locations in the sky. Adaptive optics is a more sophisticated technique that uses high-speed computers to monitor the distortion produced by turbulence in Earth's atmosphere and rapidly alter some optical components to correct the telescope image, sharpening a fuzzy blob into a crisp picture. The resolution of the image is still limited by diffraction in the telescope, but removing much of the seeing distortion produces a dramatic improvement in the detail that is visible - (a) In these images of the center of our galaxy, the adaptive optics system was turned "Off" for the left image and "On" for the right image. In the "On" image, the images of stars are sharper because the light is focused into smaller images; fainter stars are visible. (b) The laser beam shown leaving one of the Keck telescopes produces an artificial star in the field of view, and the adaptive optics system uses that laser guide star as a reference to reduce seeing distortion in the entire image.
gives astronomers a way to measure the strength of magnetic fields on the Sun.
Zeeman effect
A refracting telescope
____ is a telescope that forms images by bending light with a lens.
Rotation
____ is the motion around an axis passing through the spinning body.
Parallax
_____ is the apparent motion of an object because of the motion of the observer.
Nicolaus Copernicus
_____ was the first person to produce a detailed heliocentric model of the Universe with substantial justifying arguments.
Ultraviolet radiation
_______ is absorbed by the layer of ozone in Earth's atmosphere at an altitude of about 20 mi above Earth's surface.
11. Ultraviolet radiation from a star a. will not penetrate Earth's atmosphere and reach the ground. b. has a wavelength that is longer than the visible light emitted by the star. c. has a wavelength that is shorter than the x-rays emitted by the star. d. a and b e. b and c
a
13. Radio telescopes are important in astronomy because a. they can detect cool hydrogen. b. they have high magnification. c. the can detect interstellar dust clouds. d. they have no spherical aberration. e. they have no chromatic aberration.
a
16. A (blank) is a piece of glass with many small parallel lines etched on its surface to produce a spectrum. a. grating b. spectrograph c. photometer d. charge-coupled device e. prism
a
2. What is the wavelength of the shortest wavelength light visible to the human eye? a. 400 nm b. 4000 nm c. 7000 nm d. 700 nm e. 3 108 m
a
26. The resolving power of a telescope with a diameter of 232 cm is a. 0.05 arc seconds. b. 232 arc seconds. c. 2.32 arc seconds. d. 5 arc seconds. e. 11.6 arc seconds.
a
28. A beam of light from a laser has a wavelength of 600 nm, what is the frequency of this light? a. 5 1014 Hz b. 6000 Hz c. 3 108 m/s d. 2 10-15 Hz e. 1.8 1012 Hz
a
3. Violet light has a wavelength of approximately (blank) a. 400 nm b. 4000 nm c. 7000 nm d. 700 nm e. 3 108 m
a
Astronomers build telescopes on tops of mountains because
a and b
chromatic aberration
a distortion found in refracting telescopes because lenses focus different colors at slightly different distances
The Stratospheric Observatory for Infrared Astronomy (SOFIA),
a joint project of NASA and the German Aerospace Center (DLR), flies at altitudes up to km where it can collect infrared radiation with wavelengths that are unobservable even from high mountaintops. (b) A visual-wavelength image of the planet Jupiter (left) compared with a composite infrared image (right) using images at wavelengths of , , and microns made during SOFIA's "First Light" flight in 2010. The white stripe in the infrared image is a region of relatively transparent clouds through which the warm interior of the planet can be seen.
Planetary geologists now refer to the exterior of the newborn moon as
a magma ocean
The resolving power of a telescope is _______.
a measure of the minimum angular separation that can be seen with the telescope
Sometimes, when a theory has been refined, tested, and confirmed so often that scientists have great confidence in it is called _____
a natural law
Sometimes, when a theory has been refined, tested, and confirmed so often that scientists have great confidence in it, it is called_________
a natural law
Kepler's second law of planetary motion states that:
a planet moves at its greatest speed when it is closest to the Sun.
Kepler's second law of planetary motion states that: a planet moves at its greatest speed when it is closest to the Sun. the more massive a planet is, the more its speed will be. the mass of a planet determines how far the planet is from the Sun. all the planets move around Earth in elliptical orbits.
a planet moves at its greatest speed when it is closest to the Sun. Correct. Kepler's second law of planetary motion states that a line from a planet to the Sun sweeps over equal areas in equal intervals of time. This means that when the planet is closer to the Sun and the line connecting it to the Sun is shorter, the planet moves more rapidly to sweep over the same area that is swept over when the planet is farther from the Sun.
Extrasolar planet
a planet orbiting another star
photon
a quantum of electromagnetic energy; carries an amount of energy that depends inversely on its wavelength
A telescope that suffers from chromatic aberration and has a low light gathering power is most likely
a small diameter refracting telescope
A telescope that suffers from chromatic aberration and has a low like gathering power is most likely
a small diameter refrccting telescope
achromatic lenses
a telescope lens composed of two lenses ground from different kinds of glass and designed to bring two selected colors to the same focus and correct for chromatic aberration
equatorial mount, polar axis
a telescope mounting that allows motion parallel to and and perpendicular to the celestial equator
seeing
a term astronomers use to refer to the amount of image blurring due to atmospheric conditions
An atom can get the energy that moves an electron to a higher energy level by: transferring the electron to the ground state. preventing collisions with other atoms. absorbing a photon of electromagnetic radiation. moving the electron to a tightly bound level.
absorbing a photon of electromagnetic radiation.
Uses a high-speed computer to monitor atmospheric distortion and adjust the optics of a telescope to partially compensate for the seeing
adaptive optics
In the context of the evidence on evolution of stars, you can estimate the _____ of a star cluster by observing the distribution of the points that represent its stars in the Hertzsprung-Russell (H-R) diagram.
age
The key point to remember when considering the Hertzsprung-Russell (H-R) diagram of a star cluster in determining the evolution of stars is that all of the stars in the star cluster have the same:
age but differ in mass.
A new generation of ground-based telescopes is currently being built that overcomes the limitations of the older large telescopes. Some of these new telescopes
all of the above
A new generation of ground-based telescopes is currently being built that overcomes the limitations of the older large telescopes. Some of these new telescopes
all of the above a. use segmented mirrors. b. use mirrors that are very thin. c. use active optics to control the shape of the mirror.
Astronomers measure distances across the sky as
angles expressed in units of degrees and subdivisions of degrees
The ______ of an object is the angular distance from one edge to the other
angular diameter
A(n)__________occurs when the Moon is at its greatest distance from Earth and the Moon is new.
annular solar eclipse
Absolute visual magnitude is the:
apparent magnitude of a star observed from a distance of 10 pc.
Star brightnesses expressed in the magnitude system are known as _____, describing how the stars look to human eyes observing from Earth.
apparent visual magnitudes
Red dwarfs:
are cool and small with low luminosities.
Sunspots
are regions that are darker and cooler on the surface of the sun
Comets are found in the
asteroid belt
The average distance from Earth to the sun is called the ________
astronomical unit
Jupiter's extensive magnetosphere is responsible for _____ around the magnetic poles.
aurorae
The eerie and pretty northern and southern lights that are produced when gases in Earth's upper atmosphere glow from energy delivered by the solar wind are referred to as
aurorae
The eerie and pretty northern and southern lights that are produced when gases in Earth's upper atmosphere glow from energy delivered by the solar wind are referred to as _____.
aurorae
The Sun crosses the celestial equator going southward at the point called the
autumnal equinox
The Sun is on the celestial equator during the:
autumnal equinox and the vernal equinox.
The Sun is on the celestial equator during the: summer solstice and the winter solstice. autumnal equinox and the winter solstice. vernal equinox and the summer solstice. autumnal equinox and the vernal equinox.
autumnal equinox and the vernal equinox.
15. Infrared astronomy is often done from high-flying aircraft because a. infrared telescopes only need to get above the ozone layer. b. infrared radiation is absorbed low in Earth's atmosphere. c. infrared photons are quite energetic. d. infrared telescopes are not very heavy. e. infrared sources are very bright.
b
19. (blank) are subatomic particles traveling at tremendous velocities. a. Gamma rays b. Cosmic rays c. X-rays d. all of the above e. Photons
b
22. A telescope that suffers from chromatic aberration and has a low light gathering power is most likely a. a small diameter reflecting telescope. b. a small diameter refracting telescope. c. a large diameter refracting telescope. d. a large diameter reflecting telescope. e. the Hubble Space Telescope.
b
6. Observations of radio waves from astronomical objects suffer from poorer resolution than visible observations because a. the signals are so weak in the radio region. b. the wavelength of radio waves is much longer than the wavelengths of visible light. c. radio telescopes are generally much smaller in diameter than optical telescopes. d. it is very difficult to detect radio waves. e. radio telescopes don't use solid mirrors.
b
9. A (blank) has a few million light sensitive diodes in an array about a half-inch square. a. photometer b. charge-coupled device c. spectrograph d. photographic plate e. grating
b
why do astronomers avoid cities when building a telescope/observatory?
because light pollution, the brightening of the night sky by light scattered from artificial outdoor lighting, can make it impossible to see faint objects. astronomers locate radio telescopes as far away from civilization as possible because of similar interference with radio waves
In the context of black holes, if an object collapses to zero radius, its density and gravity _____.
become infinite
How do you increase the light gathering power of a telescope
bigger projector
In the context of electromagnetic radiation, the radiation emitted by an opaque object is called
blackbody radiation
Apparent visual magnitude is the:
brightness of a star observed from Earth
is a stellar object with such low mass that it cannot raise its central temperature high enough to sustain hydrogen fusion.
brown dwarf
L dwarfs and T dwarfs are spectral classes of _____.
brown dwarf stars
10. Radio telescopes have poor resolving power because a. their diameters are so large. b. the energy they receive is not electromagnetic radiation. c. radio waves have long wavelengths. d. a and b e. none of the above
c
14. The ability of a telescope to resolve fine detail is known as the telescope's (blank). a. light gathering power b. focal length c. resolving power d. telescope detailing e. aberration
c
21. Which of the following telescopes must be used above Earth's atmosphere? a. an optical telescope b. the VLBI telescope c. an x-ray telescope d. an infrared telescope e. none of the above
c
25. What is the magnification of a telescope and eyepiece if the telescope objective has a focal length of 200 cm and the eyepiece has a focal length of 0.2 cm a. 400 times b. 4000 times c. 100 times d. 1000 times e. 40 times
c
27. A wave traveling at a speed of 90 meters per second with a frequency of 60 Hz would have a wavelength of a. 5400 meters. b. 540 nm. c. 1.5 meters. d. 60 meters. e. 90 meters.
c
29. Your favorite radio station broadcasts at a frequency of 1.00 108 Hz, what is the wavelength of this transmission? a. 3 108 m b. 3 1016 m c. 3 m d. 0.33 m e. 3 10-8 m
c
4. (blank) has (have) wavelengths that are longer than visible light. a. Gamma-rays b. Ultraviolet light c. Infrared radiation d. X-rays e. a, b and d above
c
Stellar spectral lines
can be used as a sensitive star thermometer
According to the _____, the Moon formed elsewhere in the solar nebula and was later taken by Earth
capture hypothesis
In the context of giant stars, helium fusion produces _____ that accumulate in an inert core.
carbon and oxygen
is an imaginary sphere of very large radius surrounding Earth to which the planets, stars, Sun, and Moon seem to be attached.
celestrial sphere
electromagnetic radiation
changing electric and magnetic fields that travel through space and transfer energy from one place to another--for example, light, radio waves, and the like. Light is often referred to as this
A ____ has a few million light sensitive diodes in an array typically about a half-inch square.
charge-coupled device
A _____ is an electronic device consisting of a large array of light-sensitive elements used to record very faint images. photometer photographic plate charge-coupled device spectrograph
charge-coupled device Correct. A charge-coupled device (CCD) is an electronic device consisting of a large array of light-sensitive elements used to record very faint images. A CCD is a specialized computer chip that can contain more than a million microscopic light detectors arranged in an array about the size of a postage stamp.
is an electronic device consisting of a large array of light-sensitive elements used to record very faint images.
charge-coupled device (CCD)
Wien's law
color is proportional to the temperature emitting it
active optics
computer control of the shape of a telescope's main mirrors
Among the modes of energy transfer in stars, _____ is the least efficient of all.
conduction
The Perseid meteor shower is named after a(n)
constellation
All around the world, ancient cultures celebrated heroes, gods, and mythical beasts by naming groups of stars called
constellations
The presence of granulation is clear evidence that energy is flowing upward through the photosphere by a process known as
convection
sunspots (moon)
cooler regions caused by strong magnetic fields
The expansion of a star to giant or supergiant size _____, and so the stars move toward the upper right in the Hertzsprung-Russell (H-R) diagram.
cools the stars outer layers
On Venus, ____ are large round geological faults in the crust caused by the intrusion of magma below the crust-- or are circular bulges on Venus up to 1600 miles in diameter bordered by fractures, volcanoes, and lava flows
coronae
Is a telescope designed to capture images of faint objects such as the corona of the Sun that are near relatively bright objects.
coronagraph
Are Subatomic particles traveling a tremendous velocities
cosmic rays
The second stage of planetary evolution is
cratering and giant basin formation
1. What is the wavelength of the longest wavelength light visible to the human eye? a. 400 nm b. 4000 nm c. 7000 nm d. 700 nm e. 3 108 m
d
12. A new generation of telescopes is currently being built that overcomes the limitations of the older large telescopes. Some of these new telescopes a. use segmented mirrors. b. use mirrors that are very thin. c. use active optics to control the shape of the mirror. d. all of the above. e. none of the above
d
20. The (blank) of a telescope is a measure of its ability to show fine detail and depends on the diameter of the objective. a. light-gathering power b. focal length c. magnifying power d. resolving power e. spherical aberration
d
23. What is the ratio of the light gather power of a 5-m telescope to that of a 0.5-m telescope? a. 10 b. 0.1 c. 0.01 d. 100 e. 25
d
24. Which of the following types of radiation require the use of space based telescopes in order to collect astronomical data? I. Gamma-Ray II. Infrared III. Radio IV. Ultraviolet V. X-Ray a. II and III b. I and V c. II, III, IV d. I, IV, and V e. All of them
d
30. What is the energy of the photon whose wavelength is 400 nm? a. 1.2 1012 m b. 1.3 10-5 m c. 2.7 10-30 Joules d. 5.0 10-19 Joules e. 7.5 104 Hertz
d
5. There are (blank) nanometers in one meter. a. 1 103 b. 1 10-3 c. 1 109 d. 1 10-9 e. 400
d
Extremely high-density matter in which, due to quantum mechanical effects, pressure does not depend on temperature is termed
degenerate matter
Extremely high-density matter in which, due to quantum mechanical effects, pressure does not depend on temperature is termed__________
degenerate matter
The pressure in a gas:
depends on the tempature of the gas.
Large-impact hypothesis
describes how Earth's moon formed when an object estimated to have been at least as large as Mars smashed into proto-Earth
O Venus
Which of the following planets can be seen as a crescent from Earth?
Almost all the meteors you see in the sky are produced by meteoroids that weigh
less than 1 gram
what two powers of a telescope depend on diameter?
light gathering power and resolving power
The average distance light travels in one year is called a(n)
light year
The least important power of a telescope is
magnifying power
what are the three important "powers" of a telescope?
magnifying power (least important), resolving power, light gathering power
Spun oven (Reflectors)
make nearly hollow single piece mirror
The dark gray areas of the Moon visible from Earth are called
maria
Zenith
marks the top of the sky above your head.
The _____ of an object is a measure of the amount of matter in the object. velocity weight height mass
mass
The time a protostar takes to contract from a cool interstellar gas cloud to a main-sequence star depends on its _____.
mass
is a meteor in space before it enters Earth's atmosphere.
meteoroid
The Roche limit is the:
minimum distance between a planet and a satellite that can hold itself together by its own gravity
The Roche limit is the:
minimum distance between a planet and a satellite that can hold itself together by its own gravity.
In a reflecting telescope the objective is a _______.
mirror
The photons of blue light :
more energy than the photons of red light
The photons of blue light have:
more energy than the photons of red light.
If an object spectral lines are shifted to longer wavelengths the object is
moving away from you red shift
The short pulses and the discovery of the pulsar in the Crab Nebula are strong evidence that pulsars are _____.
neutron stars
A ground-based telescope
normally operated by astronomers and technicians working in a control room in the same building, but some telescopes are now used by astronomers many miles, even thousands of miles, from the observatory.
In the context of binary systems, a _____ is an explosion involving a white dwarf.
nova
Nuclear power plants on Earth generate energy through _____.
nuclear fission reactions
The flattening of a spherical body, usually caused by rotation, is referred to as
oblateness
In the context of Uranus's rings, the passage of the planet in front of a star is referred to as a(n)
occultation
Annular solar eclipse
occurs when the Moon is at its greatest distance from Earth and the Moon is new.
Mass
of an object is measure of the amount o matter in an object
photosphere
of the Sun is visible during an annular eclipse
what are some of the reasons astronomers put observatories on mountains?
of the best seeing, astronomers carefully select mountains where the air flow is measured to be smooth/not turbulent. Also, the air at high altitude is thin, dry, and more transparent.
A telescope performs best:
on a high mountaintop where the air is thin and steady.
A telescope performs best: in a valley where the air is calm. on a hill close to the ocean where the atmospheric turbulence is high. on a high mountaintop where the air is thin and steady. close to a valley where the seeing is poor.
on a high mountaintop where the air is thin and steady.
On the autumnal equinox, the Sun is:
on the celestial equator and moving south with respect to the equator.
Kepler's third law of planetary motion states that:
orbital period and semi-major axis are related.
The creation of a planetary atmosphere from a planet's interior is called
outgassing
_________are the large oval grooves found on Uranus's moon Miranda that indicate past geologic activity.
ovoids
The true distance of a nearby object can be calculated from the size of the apparent shift in its position relative to the background as seen from two viewing positions. That shift is called
parallax
is the term that refers to the common experience of an apparent shift in the position of a foreground object due to a change in the location of the observer's viewpoint.
parallax
One _____ equals the distance to an imaginary star that has a parallax of 1 arc second.
parsec
In the context of light curves, observations of an eclipsing binary system can directly tell astronomers not only the masses of its stars but also their _____.
diameters
The rotation of a body in which different parts of the body have different periods of rotation is referred to as
differential rotation
The rotation of a body in which different parts of the body have different periods of rotation is referred to as _____.
differential rotation
The first stage of Earth's evolution is
differentiation
During a solar eclipse, if you moved into the _____ you would be in partial shadow and would also see part of the Sun peeking around the edge of the Moon.
penumbra
During a solar eclipse, if you moved into the ______, You would be in partial shadow and would also see part of the sun peeking around the end of the moon.
penumbra
A(n) _____ is a sensitive astronomical instrument that measures the brightness of individual objects very precisely. photometer array detector grating charge-coupled device
photometer Correct. A photometer is a sensitive astronomical instrument that measures the brightness of individual objects very precisely.
A__________is a quantum of electromagnetic energy that carries an amount of energy that depends inversely on its wavelength.
photon
A _____ is a quantum of electromagnetic energy that carries an amount of energy that depends inversely on its wavelength. wave fringe photon grating
photon Correct. A photon is a quantum of electromagnetic energy that carries an amount of energy that depends inversely on its wavelength. A particle of light is called a photon, and you can think of a photon as a minimum-sized bundle of electromagnetic waves.
Particles of lights
photons
What are particles of light called
photons
Terrestrial
planets are small,rocky, dense, and metallic
Kuiper Belt Objects that are caught in a 3:2 orbital resonance with Neptune are referred to as
plutinos
Which of the following is a prototype of a new class of objects defined by the International Astronomical Union (IAU) as dwarf planets?
pluto
In a Hertzsprung-Russell (H-R) diagram, a star is represented by a _____ on the graph that tells you its luminosity and temperature.
point
Earth's axis would remain pointed constantly toward a spot near the star Polaris except for the effect of
precession
Earth's axis would remain pointed constantly toward a spot near the star Polaris except for the effect of _____
precession
When the weight of a spinning top, which causes it to tip over, combines with the top's rapid rotation and makes its axis sweep out the shape of a cone, that motion is known as _______
precession
The process by which a rotating, convecting body of conducting matter, such as in Earth's core or in the Sun's convection zone, can generate a magnetic field is referred to as the
dynamo effect
17. The technique called (blank) uses a high-speed computer to monitor atmospheric distortion and adjust the optics of a telescope to partially compensate for the seeing. a. photometry b. chromatic aberration c. active optics d. spherical aberration e. adaptive optics
e
18. The Very Long Baseline Interferometer (VLBI) a. is the highest resolution optical telescope ever built. b. is located in Arecibo, Puerto Rico. c. is a matched pair of 8 m telescopes, one of which is in Chile and the other in Hawaii. d. is an air-borne infrared telescope. e. is a set of radio telescopes linked together electronically to provide very high resolution.
e
7. (blank) has (have) wavelengths that are shorter than visible light. a. Gamma-rays b. Ultraviolet light c. Infrared radiation d. Radio e. a and b
e
8. Astronomer's build optical telescopes on tops of mountains because a. there is less air to dim the light. b. the seeing is better. c. CCDs work better when there is less oxygen in the air. d. all of the above e. a and b
e
The Very Long Baseline Interferometer (VLBI)
e. is a set of radio telescopes linked together electronically to provide very high resolution.
Through the year, the Sun moves eastward among the stars following a line called the _____, the apparent path of the Sun among the stars.
ecliptic
A(n) _____ is a closed curve around two points called the foci, such that the total distance from one focus to the curve and back to the other focus remains constant.
ellipse
a ______ is a closed curve around 2 points called the foci, such that the total distance from one focus to the curve and back to the other focus remains constant
ellipse
A(n) _____ is a closed curve around two points called the foci, such that the total distance from one focus to the curve and back to the other focus remains constant. paradigm equant ellipse deferent
ellipse Correct. An ellipse is a closed curve around two points called the foci, such that the total distance from one focus to the curve and back to the other focus remains constant.
Claudius Ptolemy created a mathematical model of the Aristotelian Universe in which a planet followed a small circle called the _____ that slid around a larger circle called the deferent. hemicycle heterocycle epicycle pericycle
epicycle Correct. Claudius Ptolemy created a mathematical model of the Aristotelian Universe in which a planet followed a small circle called the epicycle that slid around a larger circle called the deferent.
Which of the following is a Kuiper Belt Object that is quite large and has about the same diameter as Pluto but is 27% more massive?
eris
One of the main causes of slow surface evolution is the:
erosion due to moving air and water
One of the main causes of slow surface evolution is the:
erosion due to moving air and water.
By tradition, any planet in the sunset sky is called a(n)
evening star
By tradition, any planet in the sunset sky is called a(n) _____.
evening star
In the context of Schwarzschild black holes, the _____ is the boundary between the isolated volume of space-time and the rest of the Universe.
event horizon
If you move an electron from a lower energy level to a higher energy level, you can call the atom a(n)
excited atom
31. Light with a wavelength of 300 nm has a lower frequency than light with a wavelength of 500 nm.
f
32. The largest optical telescope ever constructed was a refracting telescope.
f
33. X-rays easily penetrate Earth's atmosphere and reach the ground from space.
f
36. Reflecting telescopes are no longer popular with astronomers because they are expensive and suffer from chromatic aberration.
f
38. Telescopes observing in the far ultraviolet work effectively from the tops of mountains.
f
300 nm light has a lower frequency than 500 nm light.
false
A meteor that survives its passage through the atmosphere and strikes the ground is called a meteoroid
false
A planet orbiting another star is called a protoplanet. true or false?
false
A pulsar with a pulse period of only a few milliseconds is referred to as a dotted pulsar. true or false?
false
A stable group of stars that formed and are held together by their combined gravity is called a stellar association. true or false?
false
A supernova is up to 50,000 times less luminous than a normal nova and lasts for a much shorter period.
false
All radio telescopes are refracting telescopes
false
An absorption spectrum is also called a bright-line spectrum.
false
An atom contains two or more molecules bonded together. true or false?
false
An expanding shell of gas ejected from a medium-mass star during the latter stages of its evolution is known as a black hole.
false
An expanding shell of gas ejected from a medium-mass star during the latter stages of its evolution is known as a black hole. true or false?
false
An interferometer consists of maximum of two telescopes connected to each other.
false
An interferometer reduces the resolving power of a telescope. true or false?
false
As light travels out of a gravitational field, it gains energy, and its wavelength becomes shorter. true or false?
false
Astronomers and physicists express temperatures of the Sun and other objects on the Celsius temperature scale. true or false?
false
Because of the scattering of light by dense clouds, the stars appear bluer than they should for their respective spectral types.
false
Carbonaceous chondrites are a class of iron meteorites.
false
Carbonaceous chondrites are a class of iron meteorites. true or false?
false
Convection is a mode of energy transport between materials that requires close contact between the atoms. true or false?
false
Coronae are large round ice caps on Mars. true or false?
false
Earth's magnetosphere is 100 times larger than Jupiter's.
false
Electromagnetic waves with wavelengths shorter than gamma rays are called infrared radiation.
false
Gamma rays have less energy than infrared radiation.
false
Helioseismology is the study of the differential rotation and magnetic field of the sun. true or false?
false
Herbig-Haro objects are extra solar planets.
false
In a Hertzsprung-Russell (H-R) diagram, points near the top of the diagram represent very low luminosity stars and points near the bottom represent very luminous stars.
false
In the Copernican model, Venus moves around an epicycle centered on a line between Earth and the Sun.
false
In the context of the transitions in a hydrogen atom, the Lyman series lies in the infrared region.
false
Jupiter is considered a near Earth object. true or false?
false
Maria are light-colored mountainous lunar highlands. true or false?
false
Mars has liquid water. true or false
false
Mars is an example of a Jovian planet.
false
Outflow channels on the Martian surface have remain unchanged since their formation.
false
Outflow channels on the Martian surface have remain unchanged since their formation. true or false?
false
Phobos is the smallest moon of Jupiter. true or false?
false
Reflecting telescopes are no longer popular with astronomers because they are expensive and suffer from chromatic aberration.
false
Spectroscopic parallax denotes the apparent shift in the position of a star when observed form different positions of a source. true or false?
false
Stellar parallax is the shift seen across a baseline of 2 AU rather than 1 AU. true or false?
false
Sunspots are hot spots on the Sun's surface caused by weak magnetic fields.
false
T Tauri stars are post-main-sequence stars.
false
T/f Reflecting telescopes are no longer popular with astronomers because they are expensive and suffer from chromatic aberration
false
T/f The largest optical telescope ever constructed was a refracting telescope
false
T/f light with the wavelength of 300 nm has a lower frequency been late with the wavelength of 500 nm
false
T/f x-rays easily penetrate earths atmosphere and reach the ground from space
false
The Big Dipper is an officially recognized constellation.
false
The Moon orbits eastward around Earth once a year.
false
The atmosphere you breathe today is Earth's primary atmosphere. true or false?
false
The complete magnetic cycle is 11 years long, whereas the sunspot cycle is 22 years long.
false
The condensation hypothesis proposes that the Moon formed when an object estimated to have been at least as large as Mars smashed into the proto-Earth. true or false?
false
The dominant trigger of star formation in our Galaxy is supernova explosions. true or false?
false
The eyepiece is the main mirror or lens of a telescope.
false
The hottest star in the Orion Nebula is about the same mass as the Sun. true or false?
false
The location in the Hertzsprung-Russell (H-R) diagram of giant stars fusing helium is referred to as the vertical branch.
false
The luminosity of the Sun is about 4 x 1015watts (joules per second). true or false?
false
The nearest star to the Sun is Sirius.
false
The particles inside a hot object are less agitated than the particles in a cool object. true or false?
false
The rings of Uranus are easily visible from Earth. true or false?
false
The signs of the zodiac are important to astronomy as they influence the seasons on Earth.
false
Theory predicts that protostars are nonluminous objects.
false
Ultraviolet light has wavelengths longer than violet light.
false
Uranus and Neptune are referred to as the gas giants. true or false?
false
Uranus is an example of a Terrestrial planet.
false
Uranus rotates with its equator almost parallel to its orbit. true or false?
false
Valley networks are located in Mars's northern hemisphere.
false
Valley networks are located in Mars's northern hemisphere. true or false?
false
When a star has exhausted all of its hydrogen, it is said to have reached the zero-age main sequence (ZAMS).
false
When a star has exhausted all of its hydrogen, it is said to have reached the zero-age main sequence (ZAMS). true or false?
false
When the atmosphere is unsteady, producing blurred images, the seeing is said to be good. true or false?
false
Widmanstätten patterns are mostly seen in stony meteorites.
false
Y dwarfs are substellar objects with temperature above 500 K.
false
An object in a stable orbit continuously misses Earth because of its vertical velocity. false true
false Correct. An object in a stable orbit continuously misses Earth because of its horizontal velocity.
Electromagnetic waves with wavelengths shorter than gamma rays are called infrared radiation. false true
false Correct. Electromagnetic waves with wavelengths shorter than UV light are called X-rays, and the shortest are gamma rays. Infrared radiation has wavelengths longer than the visible range.
Claudius Ptolemy discovered that the orbit of Mars is an ellipse. false true
false Correct. Johannes Kepler discovered that the orbit of Mars is an ellipse, not a circle. Thus, he abandoned the ancient belief in the circular motion of the planets.
An interferometer consists of maximum of two telescopes connected to each other. false true
false Correct. One way to improve resolving power is to connect two or more telescopes in an interferometer, which has a resolving power equal to that of a telescope as large as the maximum separation between the individual telescopes.
Gamma rays have less energy than infrared radiation. false true
false Correct. The amount of energy a photon carries depends on its wavelength. Shorter-wavelength photons carry more energy, and longer-wavelength photons carry less energy. Gamma rays have shorter wavelengths than infrared radiation.
The eyepiece is the main mirror or lens of a telescope. false true
false Correct. The main lens in a refracting telescope is called the primary lens, and the main mirror in a reflecting telescope is called the primary mirror. Both kinds of telescopes form a small, inverted image that is difficult to observe directly, so a lens called the eyepiece is used to magnify the image and make it convenient to view.
The Oort cloud is at a distance of 500 AU from the Sun.
false (100,000 AU)
Far infrared astronomy must be done from high-flying aircraft because
far infrared radiation is absorbed low in Earths atmosphere
Philosophers of the ancient world attempted to deduce truth about the Universe by reasoning from
first principles
Philosophers of the ancient world attempted to deduce truth about the Universe by reasoning from _____. careful observations geometric models first principles personal experience
first principles Correct. Philosophers of the ancient world attempted to deduce truth about the Universe by reasoning from first principles. A first principle was something that seemed obviously true to everyone and supposedly needed no further examination.
According to the _____, the Moon broke from a rapidly spinning proto-Earth. fission hypothesis large-impact hypothesis condensation hypothesis capture hypothesis
fission hypothesis
Spicules are:
flamelike jets of gas extending upward into the chromosphere and lasting 5 to 15 minutes.
The__________of a lens or mirror is the distance from that lens or mirror to the point where it focuses parallel rays of light. image distance radius of curvature focal length object distance
focal length
of a lens or mirror is the distance from that lens or mirror to the point where it focuses parallel rays of light.
focal length
The Sun fuses _____ hydrogen nuclei to make one helium nucleus.
four
Among the following electromagnetic waves, photons of which electromagnetic radiations carry the highest energy?
gamma rays
Has wavelengths shorter than visible light
gamma rays and ultraviolet light
In 1916, Einstein published his ____ that described gravity as a curvature of space-time
general theory of relativity
A(n) _____ is a model universe with Earth at the center, such as the Ptolemaic Universe. eccentric universe heliocentric universe concentric universe geocentric universe
geocentric universe Correct. A geocentric universe is a model universe with Earth at the center, such as the Ptolemaic Universe.
A(n) ____ is one in which an object orbiting Earth has an orbital period equal to the rotation period of Earth. heliocentric orbit epicyclical orbit open orbit geosynchronous orbit
geosynchronous orbit Correct. A geosynchronous orbit is one in which an object orbiting Earth has an orbital period equal to the rotation period of Earth.
A ____ is a piece of glass with many small parallel lines etched on its surface to produce a spectrum.
grating
Is a piece of glass with many small parallel lines etched on its surface to produce a spectrum
grating
A _____ is a piece of glass with thousands of microscopic parallel lines scribed onto its surface to produce a spectrum. charge-coupled device spectrograph grating photometer
grating Correct. A grating is a piece of glass or plastic with thousands of microscopic parallel lines scribed onto its surface to produce a spectrum. Different wavelengths of light reflect from the grating at slightly different angles, so white light is spread into a spectrum and can be recorded, often by a charge-coupled device camera.
The lengthening of the wavelength of a photon as it escapes from a gravitational field is known as
gravitational redshift
In the context of star masses, _____ is the key to determining mass.
gravity
The lowest energy level an electron can occupy is called the
ground state
The lowest energy level an electron can occupy is called the _____. ground state Doppler shift redshift ionization level
ground state
The lowest energy level in an atom is
ground state
The future Large Synoptic Survey Telescope (LSST)
has an -m primary mirror already completed; construction of facilities on Cerro Pachón in Chile began in 2014 (Figure 6-16). Using a -billion-pixel charge-coupled device (CCD) camera, LSST will be able to record the brightness at selected ultraviolet, visual, and infrared wavelengths of every object in one hemisphere of the sky brighter than magnitude every three nights. Astronomers and private citizens will be studying those data for decades to come.
Europa's visible surface:
has long cracks in its icy crust.
Neptune may have more atmospheric activity than Uranus because it:
has more heat flowing out of its interior.
Which of the following is true of carbonaceous chondrites?
hey contain materials left over from the formation of the Solar System.
About 75 percent of the mass of interstellar gas is _____.
hydrogen
Analysis of the solar spectrum shows that the Sun is mostly _____.
hydrogen
The two most abundant elements in the Sun are:
hydrogen and helium
Titan's surface is mainly composed of _____.
ices of water and methane
The main reason for connecting two or more telescopes in an interferometer is to:
improve resolving power.
The main reason for connecting two or more telescopes in an interferometer is to: increase diffraction fringes. improve resolving power. observe more objects in a shorter amount of time. enhance seeing.
improve resolving power. Correct. One way to improve resolving power is to connect two or more telescopes in an interferometer, which has a resolving power equal to that of a telescope as large as the maximum separation between the individual telescopes
secondary mirror
in a reflecting telescope, the mirror that reflects the light to a point of easy observation
Increasing the diameter of a reflecting telescope: decreases its magnifying power. increases its chromatic aberration. increases its light-gathering power. decreases its resolving power.
increases its light-gathering power
Increasing the diameter of a reflecting telescope:
increases its light-gathering power.
Greenhouse gases are opaque to
infrared radiation
Greenhouse gases are opaque to _____.
infrared radiation
Has wavelengths that are longer than visible light
infrared radiation
Infrared astronomy is often done from high flying aircraft because
infrared radiation is absorbed low in Earth's atmosphere
A measure of the amount of light a star produces is referred to as
intrinsic brightness
A(n)__________is a rule that the strength of an effect (such as gravity) decreases in proportion as the distance squared increases. parallel square relation direct square relation proportionate square relation inverse square relation
inverse square relation
The process in which atoms lose or gain electrons is referred to as
ionization
The process in which atoms lose or gain electrons is referred to as _____. collimation ionization a redshift the Doppler effect
ionization
The process of removing an electron from the stable nucleus is known as
ionization
Colored part of the eye
iris
Spectrograph
is a device that separates light by wavelengths to produce a spectrum.
Geocentric Universe
is a model with the Earth at the center, such as the Ptolemaic Universe
Tempature
is a number related to the average speed of partile
Photon
is a quantum of electromagnetic energy that carries an amount of energy that depends inversely on its wavelength.
Venus
is considered to be Earth's sister planet because they are similar in size and average density.
The energy of a photon
is inversely proportional to the wavelength of the light
The energy of a photon
is inversely proportional to the wavelength of the light.
The energy of a photon: is inversely proportional to the wavelength of the light. depends only on the speed of the light. is inversely proportional to the frequency of the light. depends only on the mass of the photon.
is inversely proportional to the wavelength of the light. Correct. The amount of energy a photon carries depends on its wavelength. Shorter-wavelength photons carry more energy, and longer-wavelength photons carry less energy.
The Milky Way:
is larger than most other galaxies
Blackbody radiation
is radiation emitted by an opaque object
Photosphere
is the apparent surface of the sun
A solar eclipse
is the event that occurs when the Moon passes directly between Earth and the Sun, blocking your view of the Sun.
Intrinsic brightness
is the measure of the amount of light a star produces; measured as the star's flux
Rotation
is the motion around an axis passing through the spinning body.
Eccentricity
is the number between 1 and 0 that describes the shape of an ellipse
An achromatic lens
is used to correct chromatic aberration in refracting telescopes.
Interferometry
is used to improve the resolving power
Interferometry
is used to improve the resolving power.
A(n)__________is a form of an atom with the same number of protons but a different number of neutrons. meteor isotope ion molecule
isotope
__________is an example of a Jovian planet.
jupiter
Mars's atmosphere has reduced because of the _____.
lack of an ozone layer in Mars
Nanometer is a unit of
length
Nanometer is a unit of _____.
length
Nanometer is a unit of _____. mass energy frequency length
length
Nanometer is a unit of _____. length frequency energy mass
length Correct. Nanometer is a unit of length or distance equaling one-billionth of a meter (10-9 m). It is commonly used to measure the wavelength of light
If the orbit of the moon carries it through the umbra of Earth's shadow, you see a ____
total lunar eclipse
An atmosphere containing enough greenhouse gases can trap heat and raise the temperature of a planet's surface
true
geosynchronous orbit
A(n) is one in which an object orbiting Earth has an orbital period equal to the rotation period of Earth.
is the sticking together of solid particles to produce a larger particle.
Accretion
What is the first step in the death of a star?
Accretion of a planetary nebula
Ellipse
A(n) ____ is a closed curve around two points called the foci, such that the total distance from one focus to the curve and back to the other focus remains constant.
about Symmetry
"Conservation" of a quantity is a sign of symmetry
OSupercluster
A cluster of galaxy clusters.
In the context of luminosity classes, ____ is a supergiant
Altair
A nanometer is
a unit of length
Has a few million light sensitive diodes in an array about half-inch square
charge coupled device
Meteorite
Bit of metal or rock that lands on Earth's surface
Sun's three outer layers (outside in)
Corona-chromosphere-photosphere
Identify a true statement about planets
They shine by reflecting sunlight
The neutral hydrogen Atom consists of
one proton and one electron
Most of the mass of a galaxy is contained in the
Dark matter of the galaxy
The main reason for connecting two or more telescopes in an interferometer is to
Improving resolving power
Increasing the diameter of a telescope
Increases its light gathering power
Which of the following forms of electromagnetic radiation has a longer wavelength than visible light?
Infrared radiation
Which of the following forms of electromagnetic radiation has a longer wavelength than visible light? X-rays Ultraviolet radiation Gamma rays Infrared radiation
Infrared radiation
Which of the following features of a telescope determines its light- gathering power?
The diameter of the primary mirror
Which of the following features of a telescope determines its light-gathering power?
The diameter of the primary mirror
Which of the following features of a telescope determines its light-gathering power? The length of the telescope tube The diameter of the primary mirror The magnifying power of the objective The focal length of the eyepiece
The diameter of the primary mirror
modern radio telescope
The dish reflector of a radio telescope, like the mirror of a reflecting telescope, collects and focuses radiation. Although a radio telescope's dish may be tens or hundreds of meters in diameter, the receiver antenna may be as small as your hand. Its function is to absorb the radio energy collected by the dish. Because radio wavelengths are in the range of a few millimeters to a few tens of meters, the dish only needs to be shaped to that level of accuracy, much less smooth than a good optical mirror. In fact, wire mesh works well as a mirror for all but the shortest-wavelength radio waves.
is an example of a planet
Venus
Galileo's observations of the complete set of the phases of Venus proved that
Venus orbited the Sun
Galileo's observations of the complete set of the phases of Venus proved that: Earth orbited Venus. Venus orbited the Sun. the Moon orbited Venus. Venus orbited Earth.
Venus orbited the Sun.
What aspect of Venus was MOST important in its developing differently than Earth
Venus's distance from the sun
The Sun crosses the celestial equator going northward at the point called the _____. summer solstice winter solstice autumnal equinox vernal equinox
Vernal equinox
A solar eclipse
______ is the event that occurs when the Moon passes directly between Earth and the Sun, blocking your view of the Sun.
Neap tides
______ occur when the Moon is in the first or third quarter of its lunar cycle.
Resolving power
______ refers to the ability of a telescope to reveal fine detail.
alt-azimuth mounts
a telescope mounting capable of motion parallel to and perpendicular to the horizon
A nanometer is
a unit of length.
The twisting of the axis of rotation combined with the rotation of an object causes
precession
According to the solar nebula theory, dust grains, whatever their composition, grew from microscopic size first by
condensation
The technique of connecting multiple telescopes together to combine the images from each telescope is known as
interferometry
Observations of radio waves from astronomical objects suffer from poor resolution invisible observations because
the wavelength of radio waves is much longer
is a small, dark cloud only about 1 ly in diameter that contains 10 to 1000 solar masses of gas and dust, thought to be related to star formation.
Bok globule
Evening star
Bytradition any planet in the sunser sscalet ain
Is a scientific model of Earth enclosed by a great sphere that housed the stars all one distance away
Celestial sphere
Which of the following is the largest object in the asteroid belt?
Ceres
Which of the following is a relatively large moon of Pluto? Titan Charon Europa Triton
Charon
Stars that never set below the horizon are known as
Cirumpolar stars
The problem of the place of Earth was resolved by the _____. Copernican Revolution Ptolemaic Revolution Aristotelian Revolution Newtonian Revolution
Copernican Revolution
The problem of the place of Earth was resolved by the...
Copernican Revolution
angstrom (Å)
- A unit of distance = 1 A = 5*10^-10 m - often used to measure the wavelength of light. - 1/10th of a nanometer
.X rays
- Electromagnetic radiation with short wavelengths, high frequencies, and high photon energies, between gamma-rays and ultraviolet radiation on the electromagnetic spectrum - shorter than UV rays
visible light
- makes up only a small part of the entire electromagnetic spectru
two most important factors of a telescope
- quality of the optics and the diameter of the primary lens or mirror.
_____ is a telescope that forms images by bending light with a lens.
A refracting telescope
An object in a stable orbit continuously misses Earth because of its vertical velocity. T/F
F
Emission nebulae are also called _____.
H II regions
Comet nuclei contain
carbon monoxide
The light-gathering power of a telescope is directly proportional to
the diameter of the primary mirror or lens
The light-gathering power of a telescope is directly proportional to
the diameter of the primary mirror or lens.
wavelength
the distance between successive peaks or troughs of a wave; usually represented by the greek lower case letter "lambda"
focal length
the distance from a lens or mirror to the image it forms of a distant light source
In the context of the magnitude scale, the larger the magnitude number of a star
the fainter the star is
newtonian focus
the focal arrangement of a reflecting telescope in which a diagonal mirror reflects light out the side of the telescope tube for easier access
The magnifying power of a telescope equals:
the focal length of the primary mirror or lens divided by the focal length of the eyepiece.
The magnifying power of a telescope equals: the diameter of the primary lens or mirror of the telescope. the focal length of the eyepiece divided by the focal length of the objective of the telescope. the focal length of the primary mirror or lens divided by the focal length of the eyepiece. the diameter of the eyepiece of the telescope.
the focal length of the primary mirror or lens divided by the focal length of the eyepiece. Correct. The magnifying power of a telescope equals the focal length of the primary mirror or lens divided by the focal length of the eyepiece. For example, a telescope with a primary mirror that has a focal length of 700 mm and an eyepiece with a focal length of 14 mm has a magnifying power of 50.
According to Wein's law
the hotter an object is, the shorter is the wavelength of its maximum intensity
According to Wien's law, _____. the hotter an object is, the shorter is the wavelength of its maximum intensity the cooler an object is, the shorter is the wavelength of its maximum intensity hotter objects emit less energy than cooler objects of the same size cooler objects emit more energy than hotter objects when the size of the objects are different
the hotter an object is, the shorter is the wavelength of its maximum intensity
In stellar astronomy, _____ states that the weight of each layer of a star must be supported by the layer below.
the law of hydrostatic equilibrium
In stellar astronomy, _____ states that the weight on each layer of a star is balanced by the pressure in that layer.
the law of hydrostatic equilibrium
sidereal drive
the motor and gears on a telescope that turn it westward to keep it pointed at a star
which of the following was discovered by Galileo Galilei
the mountains and valleys on the surface of the moon
frequency
the number of times a given event occurs in a given time; for a wave, the number of cycles that pass the observer in one second. represented by the greek lower case letter "nu"
schmidt-cassegrain focus
the optical design of a reflecting telescope in which a thin correcting lens is placed at the top of a cassegrain telescope
cassegrain focus
the optical design of a reflecting telescope in which the secondary mirror reflects light back down the tube through a hole in the center of the objective mirror
Kepler's first law of planetary motion implies that:
the planets move in elliptical orbits around the Sun.
Kepler's first law of planetary motion implies that: uniform circular motion is adequate to describe the motion of all the planets. the planets move at constant speeds at all points in their orbits. all the planets move around Earth in elliptical orbits. the planets move in elliptical orbits around the Sun.
the planets move in elliptical orbits around the Sun. Correct. Kepler's first law of planetary motion states that the orbits of the planets around the Sun are ellipses with the Sun at one focus.
prime focus
the point at which the objective mirror forms an image in a reflecting telescope
An observer's nadir is
the point directly opposite the observer's zenith
An observer's nadir is:
the point directly opposite the observer's zenith
The Babcock model explains:
the reversal of the Sun's magnetic field from cycle to cycle
Astronomers builds optical telescopes on top of the mountains because
there is less air to dim the light and the seeing is better
The objective of most radio telescopes is similar to the objective of a reflecting optical telescope in that
they are both concave in shape
The objective of most radio telescopes is similar to the objective of a reflecting optical telescope in that
they are both concave in shape.
Radio telescopes are important and astronomy because
they can detect cool hydrogen
Radio telescopes are important in astronomy because
they can detect cool hydrogen
The heating of a planet or satellite because of friction caused by stretching due to the gravitational influence of a nearby body is referred to as _____.
tidal heating
In the context of general relativity, time slows down in curved space-time. This is referred to as
time dilation
The main reason for building large optical telescopes on the Earths surface is
to collect as much light as possible from faint objects
The main reason for building large optical telescopes on the Earths surface is
to collect as much light as possible from faint objects.
The main reason for positioning many radio telescopes across a large area and combining the signals is
to produce higher resolution images.
A lunar eclipse that occurs when the Moon moves completely into Earth's umbral shadow is called a
total lunar eclipse
A lunar eclipse that occurs when the Moon moves completely into Earth's umbral shadow is called a _____.
total lunar eclipse
If the orbit of the Moon carries it through the umbra of Earth's shadow, you see a
total lunar eclipse
A stable cloud colliding with a shock wave can be compressed and disrupted into fragments. true or false?
true
Albedo equals 0 for a perfectly black object. true or false?
true
All of the volcanoes on Mars are shield volcanoes. true or false
true
An atmosphere containing enough greenhouse gases can trap heat and raise the temperature of a planet's surface. true or false?
true
Apparent visual magnitudes describe how stars look to human eyes observing from Earth.
true
As the Moon grows fatter from new to full, it is said to wax.
true
At least 50 percent of the stars in the Orion nebula are encircled by dense disks of gas and dust with more than enough mass to make planetary systems like ours.
true
Both Jupiter and Saturn radiate more heat than they absorb from the Sun. true or false?
true
Both reflecting and refracting telescopes may use a lens called the eyepiece.
true
Emission nebulae are produced when a hot star excites the gas near it to produce an emission spectrum. true or false?
true
In a reflecting telescope, the objective is a mirror.
true
It is a misconception to imagine that space is empty—a vacuum. true or false?
true
Light pollution makes it impossible to see faint objects.
true
Nuclear reactions in stars manufacture energy and heavy atoms under the supervision of a natural thermostat. true or false?
true
Radio astronomers face a problem of radio interference analogous to light pollution.
true
Venus is visible in the west after sunset or in the east before sunrise.
true
When an atom is in a magnetic field, the electron energy levels remain unaltered because the atom is limited to a single wavelength.
true
Ancient astronomers believed that Earth did not move because they saw no parallax. true false
true Correct. Ancient astronomers believed that Earth did not move because they saw no parallax, the apparent motion of an object because of the motion of the observer.
To adjust the speed of a planet, Ptolemy supposed that Earth was slightly off center and that the center of the epicycle moved such that it appeared to move at a constant rate as seen from a point called the equant. true false
true Correct. To adjust the speed of a planet, Ptolemy supposed that Earth was slightly off center and that the center of the epicycle moved such that it appeared to move at a constant rate as seen from a point called the equant.
is a supernova explosion caused by the collapse of a massive star.
type II supernova
The region of a shadow that is totally shaded is known as _____
umbra
A white dwarf is:
unable to generate energy by nuclear fusion
diffraction fringe
unavoidable blurred fringe surrounding any image caused by the wave properties of light. Because of this, no image detail smaller than the fringe can be seen. the size of the diffraction fringe is inversely proportional to the the diameter of the telescope. This means that the larger the telescope, the better its resolving power. Size of fringes is also proportional to to the wavelength of light being focused.
__________is one of the ice giants of the Solar System.
uranus
How do astronomers measure what stars are made of
use a spectrum
A new generation of telescopes is currently being built that overcomes the limitations of the older large Telescopes some of the new telescopes
use segmented mirrors mirrors that are very thin active optics to control the shape of the mirror
The Sun crosses the celestial equator going northward at the point called the
vernal equinox
The Elysium region is a
volcanic plain on Mars
Nicolaus Copernicus
was the first person to produce a detailed heliocentric model of the Universe with substantial justifying arguments
atmospheric windows
wavelength region in which Earth's atmosphere is transparent--at visual, infrared, and radio wavelengths
In absolute visual magnitude, Mv, the subscript V refers to the:
wavelengths of light your eye can see
An object's _____ is the force that Earth's gravity exerts on the object
weight
An object's _____ is the force that Earth's gravity exerts on the object. density weight volume mass
weight
An object's _____ is the force that Earth's gravity exerts on the object. volume density mass weight
weight Correct. An object's weight is the force that Earth's gravity exerts on the object
The sidereal drive of a telescope mounting must turn the telescope
westward about the polar axis.
Observations and stellar evolution models indicate that the central star of a planetary nebula finally must contract and become a _____.
white dwarf
Long wavelength visible light
will appear red in color to the average human eye
Long wavelength visible light
will appear red in color to the average human eye.
Ultraviolet radiation from a star
will not penetrate Earths atmosphere and reach the ground
Ultraviolet radiation from a star
will not penetrate earths atmosphere and reach the ground
The Sun reaches its most southern point at the
winter solstice
The Sun reaches its most southern point at the _____
winter solstice
The oldest Earth rocks so far discovered and dated are
zircon crystals
is a band centered on the ecliptic and encircling the sky.
zodiac
Is composed of ionized gas trapped in a magnetic arch rising up through the photosphere and the chromosphere into the lower corona.
prominence
A _____ is a collapsing cloud of gas and dust destined to become a star.
protostar
In the context of the excitation of atoms, jumps of electrons from one orbit to another are sometimes called__________. filtered jumps quantum jumps magnetic jumps transitional jumps
quantum jumps
The study of the behavior of atoms and atomic particles is referred to as:
quantum mechanics
The study of the behavior of atoms and atomic particles is referred to as: theory of computations. quantum mechanics. the electromagnetic theory. thermodynamics.
quantum mechanics.
The very long baseline interferometer
radio telescopes linked together electronically to provide a very high resolution
Among the following electromagnetic waves, photons of which electromagnetic radiations carry the lowest energy?
radio waves
In the context of the electromagnetic spectrum which of the following types of electromagnetic radiation has the longest wavelength
radio waves
Radio telescope have poor resolving power because
radio waves have long wavelengths
Radio telescopes have poor resolving power because
radio waves have long wavelengths
Radio telescopes have poor resolving power because
radio waves have long wavelengths.
Galileo & Inertia
realized friction slowed moving objects and that objects would stay in motion if there was no friction
Stars less massive than about 0.4 solar mass are referred to as _____.
red dwarfs
In the context of helium fusion, if the core of a post-main-sequence star has no nuclear reactions, the star is a
red giant
light gathering power
refers to the ability of a telescope to collect light. proportional to the area of the telescope's primary lens or mirror, that is, proportional to the "primary's diameter squared". for example, a telescope with a diameter of 2 meters has 4 times the light gathering power of a 1 meter telescope
OResolving power
refers to the ability of a telescope to reveal fine detail.
resolving power
refers to the ability of the telescope to reveal fine detail. the larger the telescope, the better its resolving power. Optical quality and atmospheric conditions also limit resolving power
Radio telescopes are ____ telescopes.
reflecting
has a main mirror called the primary mirror.
reflecting telescope
Radio telescopes are _____.
reflecting telescopes
A telescope whose objective is a lens and contains no mirrors is a ____ telescope
refracting
A telescope whose objective is a lens and contains no mirrors is aNo ____ telescope.
refracting
is a telescope that forms images by bending light with a lens
refracting telescope
Chromatic aberration occurs in a ______ telescope when ________.
refracting; different colors of light do not focus at the same point
The ____ of a telescope is a measure of its ability to show fine detail and depends on the diameter of the objective
resolving power
The ____ of a telescope is a measure of its ability to show fine detail and depends on the diameter of the objective.
resolving power
The ability of the telescope to resolve fine detail is known as the telescopes
resolving power
The part of the ident receives focus and light waves and sends it to the brain
retina
the occasional backward motion of the planets against the background of fixed stars is called _____
retrograde motion
Granulation is caused by:
rising and falling currents of gas in and just below the photosphere.
_________is one of the Jovian planets.
saturn
Conservation Laws
says that certain things cannot be created out of nothing or vanish into nothing
Only photons with wavelengths _____ can ionize hydrogen.
shorter than 91.2 nm
The time taken by the Moon to circle the sky once and return to the same position among the stars is known as the Moon's
sidereal period
A telescope that suffers from chromatic aberration and has a low light-gathering power is most likely a:
small diameter refracting telescope.
Asteroids, comets, and meteroids are examples of
space debris
A _____ is a device that separates light by wavelengths to produce a spectrum. lens mirror interferomoter spectrograph
spectrograph Correct. A spectrograph is a device that separates light by wavelengths to produce a spectrum. To analyze light in detail, you need to spread the light out according to wavelength into a spectrum.
A _____ is a group of stars that formed together and orbit a common center of mass.
star cluster
The Hertzsprung-Russell (H-R) diagram can help you understand different kinds of _____.
stars
The violent explosive death of an aging massive star results in a
supernova
In the context of the Jovian rings, moons:
supply the rings with particles.
34. Light can behave as a particle or as a wave.
t
35. The amount of energy a photon carries depends on its wavelength.
t
37. One of the advantages of charge-coupled devices over photographic plates is that a CCD can record bright and faint objects on the same exposure.
t
optical telescopes
telescopes that collect visible light
radio telescopes
telescopes that gather radio waves/ resemble giant TV satellite dishes
The ___ of a gas is a measure of the average speed of the particles in the Gass
temperature
Absolute zero is
temperature at which Adams have no remaining energy from which we can extract heat
The set of star types, called the spectral sequence, is important because it is a _____.
temperature sequence
Ancient philosophers and astronomers accepted without question—as first principles—that: heavenly objects must move in circular paths at varying speeds. the planets are made of rock and gas, much like Earth. the Earth is motionless at the center of the Universe. there are many galaxies in the Universe.
the Earth is motionless at the center of the Universe.
Ancient philosophers and astronomers accepted without question—as first principles—that: there are many galaxies in the Universe. heavenly objects must move in circular paths at varying speeds. the planets are made of rock and gas, much like Earth. the Earth is motionless at the center of the Universe.
the Earth is motionless at the center of the Universe. Correct. Ancient philosophers and astronomers accepted without question—as first principles—that heavenly objects must move on circular paths at constant speeds, and that the Earth is motionless at the center of the Universe.
magnifying power
the ability of a telescope to make images bigger. the magnifying power of a telescope equals the focal length of the primary mirror or lens divided by the focal length of the eyepiece. In other words, you can change the magnification of a telescope simply by changing the eyepiece
More than 2000 years ago, Hipparchus compared the positions of some stars with their positions recorded nearly two centuries previously and realized that: the celestial poles and equator were slowly moving across the sky. the stars were moving closer to each other. the celestial poles and equator remained stationery. the stars were moving across the sky randomly.
the celestial poles and equator were slowly moving across the sky.
Which if the following planets can be seen as a crescent from Earth?
Venus
Which of the following planets can be seen as a crescent from Earth? Saturn Jupiter Venus Mars
Venus
Which of the following planets is an example of a Terrestrial planet? Venus Uranus Neptune Jupiter
Venus
Which of the following planets' average density is closest to that of Earth? Mars Venus Mercury Neptune
Venus
_____ is an example of a planet. Rigel Venus Pluto Sirius
Venus
Which of the following sequences of electromagnetic radiation is arranged in the order of increasing energy?
Visible light, ultraviolet radiation, X-rays, and gamma rays
What is the relationship between color and wavelength for light?
Wavelength increases from blue light to red light
Which of the following is true of visible light?
Wavelength increases from violet light to red light
Which of the following is true of visible light? Wavelength decreases from blue light to green light. Wavelength increases from violet light to red light. Wavelength decreases from violet light to red light. Wavelength increases from red light to orange light.
Wavelength increases from violet light to red light.
Which wavelength radiated the most energy? Wavelengths of maximum intensity Wavelength of minimum intensity All wavelengths radiate the same amount of energy Wavelength and energy are not related
Wavelength of maximum intensity
The largest fully steerable radio telescope is in
West Virgina
The largest fully steerable radio telescope is in _____. California Alaska New Mexico West Virginia
West Virginia
By tradition, any planet in the sunset sky is called a(n) _____. exoplanet pulsar planet morning star evening star
Evening Star
Gamma rays
What type of electromagnetic radiation has the smallest wavelength?
Solar Nebula Theory
Explains the basic characteristics of the Solar System, including the shape, types of planets, and the common age
Claudius Ptolemy discovered that the orbit of Mars is an ellipse. T/F
F
Electromagnetic waves with wavelengths shorter than gamma rays are called infrared radiation. T/F
F
If the distance from Earth to the Moon were doubled, the gravitational force between them would increase by a factor of 22, or 4. T/F
F
In the Copernican model, Venus moves around an epicycle centered on a line between Earth and the Sun. T/F
F
In the context of granulation, convection occurs when hot fluid sinks and cool fluid rises. T/F
F
Spiral arms are concentrated at the center of our Galaxy. T/F
F
Spring tides and neap tides are caused solely by the effects of the Sun. T/F
F
The average distance from Venus to the Sun is about 2 AU. T/F
F
The nearest star to the Sun is Sirius. T/F
F
The particles inside a hot object are less agitated than the particles in a cool object. T/F
F
300 nm light has a lower frequency than 500 nm light.
False
Ancient Astronomers called the brightest stars in a constellation sixth-magnitude stars
False
Ancient astronomers called the brightest stars in a constellation sixth-magnitude stars (T or F)
False
Claudius Ptolemy discovered that the orbit of Mars is an ellipse
False
Electromagnetic waves with wavelengths shorter than gamma rays are called infrared radiation
False
Electrons in an atom are positively charged
False
In the H-R diagram, points near the top of the diagram represents very low luminosity stars and points near the bottom represents very luminous stars
False
In the copernican model, Venus moves around an epicycle centered on a line between Earth and the sun (T or F)
False
In the distance from Earth to the moon were doubled, the gravitational force between them would increase by a factor of 22, or 4 (T or F)
False
Interferometry is easiest to use with telescopes that observe at very short wavelengths
False
Telescopes observing in the far ultraviolet can work from high-flying aircraft
False
Telescopes observing in the far ultraviolet can work from high-flying aircraft.
False
The Big Dipper is an officially recognized constellation
False
The average distance from Venus to the sun is about 2 AU (T or F)
False
The centers of stars are many millions of degrees cooler than their surfaces
False
The largest optical telescope ever constructed was a refracting telescope.
False
The light colored mountainous lunar highlands are called maria. T or F
False
The moon orbits eastward around Earth once a year (T or F)
False
The sidereal drive on a telescope mounting must turn the telescope eastward about the polar axis.
False
X-rays easily penetrate Earths atmosphere and reach the ground from space.
False
an object in a stable orbit continuously misses Earth because of its vertical velocity (T or F)
False
airborne telescopes
In addition to the atmospheric windows at visual and radio wavelengths you have already learned about, there are also a few narrow windows at short infrared wavelengths accessible from the ground, especially from high mountains such as Mauna Kea (Figure 6-13). However, most infrared wavelengths are blocked, especially by water vapor absorption. Also, Earth's atmosphere itself produces a strong infrared "glow." Observations at very long infrared wavelengths can only be made using telescopes carried to high altitudes by aircraft or balloons or launched entirely out of the atmosphere onboard spacecraft. (Notice that the reasons to put an infrared telescope above the atmosphere are not the same as the reasons to send an optical telescope into space.) Starting in the 1960s, NASA developed a series of infrared observatories with telescopes carried above Earth's atmospheric water vapor by jet aircraft. Such airborne observatories are also able to fly to remote parts of Earth to monitor astronomical events not observable by any other telescope. The modern successor to those earlier flying observatories is the Stratospheric Observatory for Infrared Astronomy, or SOFIA (Figure 6-18). SOFIA consists of a -m telescope looking out an opening with a rollback door in the left side of a modified Boeing aircraft
Which of the following forms of electromagnetic radiation has longer wavelength than visible light?
Infrared radiation
Which of the following types of electromagnetic radiation has the lowest energy?
Infrared radiation
____ has (have) wavelengths that are longer than visible light.
Infrared radiation
____ is absorbed by water in Earths atmosphere and requires that telescopes for observing at these wavelengths be placed on mountain tops or in space.
Infrared radiation
Which of the following forms of electromagnetic radiation has a longer wavelength than visible light? Ultraviolet radiation Infrared radiation Gamma rays X-rays
Infrared radiation Correct. Infrared radiation has longer wavelengths than the maximum wavelength of visible light. The wavelength of infrared radiation ranges from 700 nanometers to about 1 millimeter.
Spectra are often represented as graphs of
Intensity vs wavelength
is microscopic solid grains in the interstellar medium.
Interstellar dust
_____ is the process in which dust scatters blue light out of starlight and makes the stars look redder.
Interstellar reddening
A measure of the amount of light a star produces is referred to as
Intrinsic brightness
Which of the following is the most geologically active moon? Callisto Ganymede Io Europa
Io
The process in which atoms lose or gain electrons is referred to as
Ionization
Ellipse
Is a closed curve around two points called the foci, such that the total distance from one focus to the curve and back to the other focus remains constant
A starburst galaxy is a galaxy that
Is undergoing a rapid surge of star formation
Which of the following statement is true of the solar wind?
It can be considered an extension of the corona
Which of the following statements is true of the solar wind?
It can be considered an extension of the corona.
Which of the following statements is true of the chromosphere? It has a depth greater than Earth's diameter. It can be seen during a total solar eclipse. It lies below the photosphere. It consists of nonionized atoms.
It can be seen during a total solar eclipse
Which of the following statements is true of the chromosphere?
It can be seen during a total solar eclipse.
Identify a true statement about the Sun. -It is the smallest star in the universe -It is at a distance of 2 AU from Earth. -It generates it own energy -It shines by reflecting light from the Moon.
It generates its own energy
Which of the following statements is true of Uranus?
It has a deep mantle of partly solid water.
Which of the following is true of Mars?
It has a heavily cratered crust marked by volcanoes.
Which of the following is true of Earth's interior?
It has a low-density crust.
Which of the following statements is true of Jupiter?
It has a slightly flattened shape.
Which of the following statements is true of Uranus when compared with Jupiter or Saturn?
It has much less heat flowing out of its interior than Jupiter or Saturn.
Which of the following is true of Mercury?
It has negligible atmosphere.
Which of the following statements is true of the dynamo effect?
It is believed to operate in the liquid metal of Earth' core to produce Earth's magnetic field
Which of the following statements is true of the dynamo effect?
It is believed to operate in the liquid metal of Earth's core to produce Earth's magnetic field.
Which of the following statements best describes one astronomical unit (AU)? It is equal to the average distance of the Sun from Earth. It is the distance from Earth to the Moon. It is the average distance between two stars in the Milky Way. It is the distance that light travels in a vacuum in one year.
It is equal to the average distance of the Sun from Earth.
Which of the following is true of the Moon's synodic period?
It is longer than the Moon's sidereal period.
Which of the following is true of a first principle?
It is something that seems obviously true and needs no further examination
Which of the following is true of a first principle? It is something that is true but needs a lot of examination to be proven true. It is something that is false but appears true without proper examination. It is something that seems obviously true and needs no further examination. It is something that is obviously false and needs no further examination.
It is something that seems obviously true and needs no further examination.
What is true of Sagittarius A
It is supermassive black hole
Which of the following statements is true of absolute zero?
It is the temperature at which an object contains no thermal energy that can be extracted
Which of the following statements is true of absolute zero? It is the highest temperature at which the motion of particles is maximum. It is equivalent to zero degrees Celsius. It is the temperature at which an object contains no thermal energy that can be extracted. It is the temperature at which water freezes.
It is the temperature at which an object contains no thermal energy that can be extracted
Which of the following is true of chromatic aberration
It occurs when different colors are focus at slightly different distances
Which of the following is true of chromatic aberration?
It occurs when different colors are focused at slightly different distances.
Which of the following is true of chromatic aberration? It is the main cause of seeing. It mostly occurs in reflecting telescopes. It occurs when different colors are focused at slightly different distances. It is a natural phenomenon that occurs because of high turbulence in Earth's atmosphere.
It occurs when different colors are focused at slightly different distances. Correct. Chromatic aberration is a distortion found in refracting telescopes because lenses focus different colors at slightly different distances. Images are consequently surrounded by color fringes. When light is refracted through glass, shorter wavelengths bend more than longer wavelengths. As a result, you see a color blur around every image. This color separation is called chromatic aberration, and it can be only partially corrected.
In the context of Jupiter, which of the following statements is true of belt-zone circulation?
It results from Jupiter's rapid rotation.
Philosophers of the ancient world attempted to deduce truth about the Universe by reasoning from _____. geometric models careful observations first principles personal experience
First Principles
Philosophers of the ancient world attempted to deduce the truth about the Universe by reasoning from
First principles
Spicules
Flamelike jets of gas extending upward into the chromosphere and lasting 5 to 15 minutes.
Advanced technology allows astronomers to measure the flow of energy through a surface to determine precise measurements of star brightness. THis measurement is called
Flux
Which if the following is true of Claudius Ptolemy?
For him, first principles took second place to accuracy
Which of the following is true of Uranus?
It rotates on its side with its equator almost perpendicular to its orbit.
A lunar eclipse can only occur if the moon is
Full
Eight Lunar Moon Phases
Full Moon-Waxing gibbous-First quarter-waxing crescent-New moon-Waning crescent- Thirds quarter-waning gibbous
Which of the following indicates that the sun must be gas from its surface to its center
It's low density high temperature
Which of the following indicated that the Sun must be gas from its surface to its center?
Its low density and high temperature
Which of the following indicates that the Sun must be gas from its surface to its center? Its hot spots on the photosphere Its low density and high temperature Its weak magnetic field and small diameter Its limited gravitational force
Its low density and high temperature
Galileo discovered the satellites of
Jupiter
In the context of the electromagnetic spectrum which of the following types of electromagnetic radiation has the smallest wavelength
Gamma rays
In the context of the electromagnetic spectrum, which of the following types of electromagnetic radiation has the smallest wavelength?
Gamma rays
In the context of the electromagnetic spectrum, which of the following types of electromagnetic radiation has the smallest wavelength? X-rays Visible light Gamma rats Radio waves
Gamma rays
Which of the following types of electromagnetic radiation has the highest frequency?
Gamma-rays
is the largest moon in the Solar System.
Ganymede
Ptolemy's model of the universe was
Geocentric
Which of the following is the largest of the Jovian planets? Neptune Saturn Jupiter Uranus
Jupiter
Which planet has moons now referred to as the Galilean Moons?
Jupiter
If you see the crescent moon setting in the west what time of day is it?
Just after sunset
types of energy!!
Kinetic 1/2 mass x velocity^2 Gravitational (potential energy) g x height x mass **g - acceleration of gravity at the Earth's surface: 9.8 m/s2 Electrical (electro/magnetic force) Chemical (electric force between atoms and molecules) Nuclear (strong force between protons and neutrons) Thermal (motion of atoms) Radiation (electro/magnetic waves) Mass (can be converted into energy) Dark Energy (property of the vacuum)
The warmer brown dwarfs fall in spectral class _____.
L
is the gradual increase in the surface temperature of Earth caused by human modifications to Earth's atmosphere.
Global warming
The visual patterns on the photospher made up of dark-edged regions is known as
Granulation
What force inevitably kills stars?
Gravity
When Voyager 2 flew by Neptune in 1989, the largest feature observed was the _____, which is roughly the size of Earth.
Great Dark Spot
Which of the following is true of Galileo Galilei?
He applied his careful observations of the sky to determine the place of Earth.
Which of the following is true of Galileo Galilei? He publically defended the geocentric model of the Universe. He invented the telescope. He applied his careful observations of the sky to determine the place of Earth. He was the first person to look at the sky through a telescope.
He applied his careful observations of the sky to determine the place of Earth. Correct. Galileo Galilei was the first person to observe the sky carefully and apply his observations to the main theoretical problem of the day—the place of Earth.
Which of the following is true of Johannes Kepler
He discovered that the orbit of mars is an eclipse, not a circle
Which of the following did Kelper study? Circular Orbits Laws of planetary motion Parallax All of the above
Laws of planetary motion
What makes it impossible to see faint objects
Light pollution
Distance light travels in one year.
Light-year
_____ is absorbed by water vapor in Earth's lower atmosphere. Long-wavelength infrared radiation Long-wavelength ultraviolet radiation X-ray radiation Radio wave radiation
Long-wavelength infrared radiation Correct. Water vapor in Earth's lower atmosphere absorbs long-wavelength infrared radiation. Only visible light, some short-wavelength infrared radiation, and some radio waves reach Earth's surface through what are called atmospheric windows.
H-R diagram
Luminosity and Absolute magnitude are on the left and right side, while Spectral type and Temperature are on top and bottom. Supergiants are highest on the scale, while giants are the second highest. Main sequence stars are in a large array varying in temperature and stretched from high and low luminosity. White dwarfs are located at the bottom left, with low luminosity, and low temperature
Which of the following stars is an example of a spectroscopic binary system?
Mizar
Advances in Modern Telescope Design
Modern computer technology has made possible significant advances in telescope design: 1. Simpler, stronger mountings ("Alt-azimuth mountings") to be controlled by computers 2. Spun-oven mirrors that are hollow inside so light but sturdy 3. Lighter mirrors with lighter support structures, to be controlled dynamically by computers - ultra thin mirrors and segmented mirrors
The gravitational attraction between the Earth, ___, and ___ create the tides on Earth
Moon; sun
The photons of blue light have
More energy than the photons of red light
Blue light differs from red light in that
More than one of the above
Length
Nanometer is unit of _____.
____ occur when the moon is the first or third quarter of its lunar cycle
Neap tides
____ occur when the Moon is in the first or third quarter of its lunar cycle. Total solar eclipses Neap tides Spring tides Annular eclipses
Neap tides Correct. At first- and third-quarter moons, solar tides cancel out part of lunar tides so that high and low tides are not extreme. These are called neap tides.
One of the giant ice giants of the solar system
Neptune
Which of the following objects is a part of the Solar System? Coku Tau/4 Sirius Neptune Procyon
Neptune
Which of the following metals is a constituent of iron meteorites?
Nickel
Which of the following metals is a constituent of iron meteorites? Nickel Potassium Copper Zinc
Nickel
Kepler's third law of planetary motion states that....
Orbital period and semi-major axis are related.
are the large oval grooves found on Uranus's moon Miranda that indicate past geologic activity.
Ovoids
A _______ is a commonly accepted set of scientific ideas and assumptions
Paradigm
During a solar eclipse, if you moved into the__________, you would be in partial shadow and would also see part of the Sun peeking around the edge of the Moon. penumbra south point north point umbra
Penumbra
First principles
Philosophers of the ancient world attempted to deduce truth about the Universe by reasoning from ____.
A ___ is a quantum of electromagnetic energy that carries an amount of energy that depends inversely on its wavelength
Photon
A(n) ______ is a model of the Universe with the Sun at the center, such as the Copernican Universe
Heliocentric Universe
The sun in primarily composed of hydrogen and ____
Helium
The ignition of helium in the core of a star changes the structure of the star. The star now makes energy in two locations by different processes
Helium fusion in the core and hydrogen fusion in the surrounding shell
is a small nebula that varies irregularly in brightness, evidently associated with star formation.
Herbig-Haro object
is a graph that separates the effects of temperature and surface area on stellar luminosities and enables astronomers to sort the stars according to their diameters.
Hertzsprung-Russell diagram
Which of the following element is NOT created in stars
Hydrogen
Which of the following is the most abundant element in the universe
Hydrogen
In the context of a star's spectrum, which of the following statements is true of a giant star?
Hydrogen atoms in its atmosphere do not often collide with each other
Venus
Planet that can be seen as a crescent from Earth.
Forms when an aging giant expels its outer atmosphere in repeated surges
Planetary Nebula
is one of the small bodies that formed from the solar nebula and eventually grew into protoplanets.
Planetesimal
Solar nebula theory supposes that
Planets form in rotating disks of gas and dust around young stars
Which of the following is a prototype of a new class of objects defined by the International Astronomical Union (IAU) as dwarf planets? Triton Pluto Uranus Titan
Pluto
Energy
(1/2 mass x velocity2)
Angular momentum
*(mass x velocity x distance) *planet orbits
Momentum
*(mass x velocity) *constant unless a force is acting
Seeing
*Amount of atmospheric turbulence **Good seeing is about 1 arcsec **Excellent seeing is about 0.5 arcsec *No atmosphere in space, so always get the maximum resolution of the telescope
Reflectors
*Largest telescopes today *One optical surface *Can be made lighter than a refractor of the same size *No "chromatic aberration" - prism effect
Refractors
*Need very uniform glass *Must polish 4 surfaces *Very heavy and hard to support *Limit is about 1 meter aperture *Largest refractor is 40 inch diameter
Newton & Planet Orbits
*Newton's laws assume an "absolute time" (but in E's General Relativity clocks run more slowly in gravity field) *therefore, Newton's laws are an approximation for places with small gravitational fields
good conditions for Optical/IR Telescopes
*No light pollution *No humidity *Quiet atmosphere *High altitude
Galileo & the Sun
*Saw dark regions AKA "sunspots" *used sunspots to find that the sun rotates
Emmy Noether (1920s)
*conservation laws result from symmetries in nature (basis for modern particle physics) *Symmetries allow transformations that do not change the "system" *Translation= momentum conservation *Rotation= angular momentum conservation *Time zero point= Energy conservation
Galileo & Venus
*discovered it went through phases * this discovery proved Venus orbits the sun, not the Earth
average wavelength of visible light
- .0005 mm - ranges from 400 to 700nm or 4000 to 7000 A - Light with wavelengths at the short-wavelength (400nm) end of the visible spectrum appears violet to your eyes, and light with wavelengths at the long-wavelength (700nm) end appears red
chromatic aberration
- A distortion found in refracting telescopes because lenses focus different colors at slightly different distances. Images are consequently surrounded by color fringes
photon
- A quantum of electromagnetic energy; carries an amount of energy that depends inversely on its wavelength. - A particle of electromagnetic radiation - The amount of energy a photon carries is inversely proportional to its wavelength
refracting telescope design
- A refracting telescope's primary lens is much more difficult to manufacture than a mirror of the same size. The interior of the glass must be pure and flawless because the light passes through it. Also, if the lens is achromatic, it must be made of two different kinds of glass requiring four precisely ground surfaces. - use a big lens at the top of the tube to bend the light and bring it to a focus. That lens, the primary lens, has a long focal length and produces a tiny upside down image that is hard to view. A second, short focal length lens called the eyepiece is used to magnify the image and guide the light into the eye, making the image convenient to view.
eyepiece
- A short-focal-length lens used to enlarge the image in a telescope; the lens nearest the eye.
achromatic lenses
- A telescope lens composed of two lenses ground from different kinds of glass and designed to bring two selected colors to the same focus and correct for chromatic aberration.
Refracting telescopes
- A telescope that forms images by bending (refracting) light with a lens. - uses a primary lens to focus starlight into an image that is magnified by another lens called an eyepiece. The primary lens has a long focal length, and the eyepiece has a short focal length. - primary lens is main lens in a refracting telescope.
radio telescopes
- A telescope that gathers and focuses electromagnetic energy with microwave and radio wavelengths. - extremely difficult to make a lens that can focus radio waves, so all radio telescopes, including small ones, are reflecting telescopes; the dish is the primary mirror - affected by atmospheric seeing, but less than optical telescopes, so they do not benefit much in this respect by being located on mountains - don't have eyepieces, but they do have instruments that examine the radio waves focused by the telescope, and each such instrument would, in effect, have its own magnifying power.
optical telescopes
- A telescope that gathers and focuses visible light - intended for the study of visible light - performs better on a high mountaintop where the air is thin and steady. But even in that situation, Earth's atmosphere spreads star images at visual wavelengths into blobs about .5 to 1 arc second in diameter.
Increasing the diameter of a telescope I. increases its light gathering power. II. increases its resolving power. III. increases it magnifying power. IV. increases its chromatic aberration.
I & II
reflecting telescopes
- A telescope that uses a concave mirror to focus light into an image. - uses a primary mirror to focus the light by reflection. In this particular reflector design, called a Cassegrain telescope, a small secondary mirror reflects the starlight back down through a hole in the middle of the primary mirror to the eyepiece lens. - the main mirror in a reflecting telescope - all large astronomical telescopes built since the start of the th century have been reflecting telescopes - the curved primary mirror at the bottom of the tube reflects the light to a focus. To make the light come out the bottom of the tube for convenient viewing, astronomers place a secondary mirror at the top of the tube to reflect the light back down the tube through a hole in the primary mirror to a focus. These optical surfaces are coated with a thin film of aluminum alloy to make them highly reflective.
nanometer (nm)
- A unit of length equal to 10^-9 m - used to measure wavelength of light
spectrum
- An arrangement of electromagnetic radiation in order of wavelength or frequency. - visible light: extending from red to violet
seeing
- Atmospheric conditions on a given night. When the atmosphere is unsteady, producing blurred images, the seeing is said to be poor. - even under relatively good seeing conditions, the detail visible through a large telescope is limited not by its diffraction fringes but by the turbulence of the air through which the telescope must look.
radio waves
- Beyond the infrared part of the electromagnetic spectrum - Electromagnetic wave with extremely long wavelength, low frequency, and small photon energy. used for FM, television, military, government, and cell phone radio transmissions have wavelengths of a few centimeters to a few meters, whereas - AM and other types of radio transmissions have wavelengths of a few hundred meters to a few kilometers
diffraction fringes
- Blurred fringe surrounding any image caused by the wave properties of light. Because of this, no image detail smaller than the fringe can be seen. - Stars are so far away that their images are points, but the wavelike characteristic of light causes each star image to be surrounded with diffraction fringes, much magnified in this computer model. (b) Two stars close to each other have overlapping diffraction fringes and become impossible to detect separately. - he size of the diffraction fringes is inversely proportional to the diameter of the telescope. This means that the larger the telescope, the better its resolving power. However, the size of diffraction fringes is also proportional to the wavelength of light being focused. In other words, an infrared or radio telescope has less resolving power than an optical telescope of the same size.
telescopes
- Both refracting and reflecting telescopes form an image that is small, inverted, and difficult to observe directly - an eyepiece normally is used to magnify the image and make it convenient to view - Short focal-length lenses and mirrors must be made with more curvature than ones with long focal lengths. The surfaces of lenses and mirrors then must be polished to eliminate irregularities larger than the wavelengths of light
electromagnetic radiation
- Changing electric and magnetic fields that travel through space and transfer energy from one place to another—for example, light, radio waves, and the like. - light it is made up of both electric and magnetic fields - travels through space at a speed of 3*10^8 m/s (186,000 mi/s); this is commonly referred to as the speed of light, symbolized by the letter , but it is in fact the speed of all types of electromagnetic radiation.
- modern telescope mirrors
- Conventional primary mirrors are thick to prevent the optical surface from sagging and distorting the image as the telescope is moved around the sky. But large mirrors can weigh many tons, are difficult to support, and are expensive to make. Also, large mirrors take a long time to cool after nightfall. Changes in shape as the mirror cools down make the telescope difficult to focus and cause image distortions.
relationship between energy a photon carries and wavelength
- E = hc/wavelength - h is Planck's constant and = 6.63 *10^-34 joules - c = speed of light - The inverse proportion means that as wavelength gets smaller energy (E) gets larger: Shorter-wavelength photons carry more energy, and longer-wavelength photons carry less energy - short wavelength, high frequency, and large photon energy go together; long wavelength, low frequency, and small photon energy go together.
infrared (IR) radiation
- Electromagnetic radiation with wavelengths intermediate between visible light and radio waves. - Beyond the red end of the visible spectrum - wave lengths range from 700nm to 1mm (1 million nm) - skin senses it as heat - discovered in the year 1800, the first known example of "invisible light"
ultraviolet (UV)
- Electromagnetic radiation with wavelengths shorter than visible light but longer than X-rays. -electromagnetic waves shorter than violet
microwaves
- Electromagnetic wave with wavelength, frequency, and photon energy intermediate between infrared and radio waves. - Beyond the infrared part of the electromagnetic spectrum - used for cooking food in a microwave oven, as well as for radar and some long-distance telephone communications, have wavelengths from a few millimeters to a few centimeters
short wavelengths
- Extremely short-wavelength, high-frequency photons, such as X-rays and gamma-rays, have high energies and can be dangerous. Even ultraviolet photons have enough energy to harm you
lower-energy infrared photons
- Individually they have too little energy to affect skin pigment, a fact that explains why you can't get a tan from a heat lamp. Only by concentrating many low-energy photons in a small area, as in a microwave oven, can you transfer significant amounts of energy
reflecting telescope usage
- Light does not pass through any glass, so reflecting telescopes do not suffer from chromatic aberration. That color distortion has made reflecting telescopes the preferred form among modern astronomers. Also notice that the focused light in a reflecting telescope goes up the tube and back down to the focus. That makes the tube shorter than that of a similar refracting telescope, and among large telescopes, a short tube weighs significantly less and is easier to support without vibration. A short tube also means the observatory building and dome can be smaller. Another important advantage is that astronomers can make mirrors much bigger than lenses. That makes giant telescopes possible.
High energy astronomy
- Like infrared-emitting objects, gamma-ray, X-ray, and ultraviolet sources in the Universe are difficult to observe because the telescopes must be located high in Earth's atmosphere or in space. Also, high-energy photons are difficult to bring to a focus. The first high-energy astronomy satellite, Ariel 1, was launched by the United Kingdom in 1962 and made solar observations in the ultraviolet and X-ray segments of the electromagnetic spectrum. Since then, many more space telescopes have followed Ariel's lead. Some high-energy astronomy satellites such as XMM-Newton, an X-ray observatory developed by a consortium of European and British astronomers, have been general-purpose telescopes that observe many different kinds of objects. In contrast, some space telescopes are designed to study a single question or a single object. For example, the Japanese satellite Hinode (pronounced, hee-no-day) studies the Sun continuously at visual, ultraviolet, and X-ray wavelengths, and the Kepler space observatory operated for years detecting planets orbiting stars other than the Sun. The largest X-ray telescope to date is the Chandra X-ray Observatory (CXO). Chandra operates in an orbit that extends a third of the way to the Moon so that it spends percent of the time above the belts of charged particles surrounding Earth that would produce electronic noise in its detectors. (Chandra is named for the late Indian American Nobel laureate Subrahmanyan Chandrasekhar, who was a pioneer in many branches of theoretical astronomy.) Focusing X-rays is difficult because they penetrate into most mirrors, so astronomers devised cylindrical mirrors in which the X-rays reflect at shallow angles from the polished inside of the cylinders to form images on X-ray detectors, as shown in Figure 6-20. The Chandra observatory has made important discoveries about everything from star formation to monster black holes in distant galaxies that will be described in later chapters. - X-rays that hit a mirror at grazing angles are reflected like a pebble skipping across a pond. Thus, X-ray telescope mirrors like the ones in Chandra are shaped like barrels rather than dishes.
magnifying power
- M = (Fp/Fe) - The magnifying power of a telescope equals the focal length of the primary mirror or lens divided by the focal length of the eyepiece.
modern telescopes
- Other telescopes are fully automated and operate without direct human supervision. That, plus continuous improvement in computer speed and storage capacity, has made possible huge surveys of the sky in which millions of objects have been observed or are planned for observation. For example, the Sloan Digital Sky Survey (SDSS) mapped the entire Northern Hemisphere sky, measuring the position and brightness of million stars and galaxies at five ultraviolet, optical, and infrared wavelengths.
For most of the th century, astronomers faced a serious limitation on the size of astronomical telescopes
- Telescope mirrors were made thick to avoid bending that would distort the reflecting surface, but those thick mirrors were heavy
Light-gathering power
- The ability of a telescope to collect light; proportional to the area of the telescope's objective lens or mirror. - A large-diameter telescope gathers more light and produces a brighter image than a smaller telescope of the same focal length. - proportional to the area of the telescope primary lens or mirror; a lens or mirror with a large area gathers a large amount of light. The area of a circular lens or mirror written in terms of its diameter D is (pi* d^2)/4 .
resolving power
- The ability of a telescope to reveal fine detail; depends on the diameter of the telescope objective. - Aside from diffraction, two other factors—optical quality and atmospheric conditions—limit resolving power. A telescope must have high-quality optics to achieve its full potential resolving power. Even a large telescope reveals little detail if its optical surfaces are marred by imperfections.
light pollution .
- The illumination of the night sky by waste light from cities and outdoor lighting, which prevents the observation of faint objects
primary mirror
- The main optical element in an astronomical telescope. The large lens at the top of the telescope tube or the large mirror at the bottom.
space telescopes
- The most successful observatory in history, the Hubble Space Telescope (Figure 6-19a), is named after Edwin Hubble, the astronomer who discovered the expansion of the Universe. The Hubble telescope, also known as HST, was launched in 1990 and contains a -m mirror plus three instruments with which it can observe visible light plus some ultraviolet and infrared wavelengths. Its greatest advantage is the lack of seeing distortion, located completely above Earth's atmosphere. Hubble therefore can detect fine detail, and because it concentrates light into sharp images, it can detect extremely faint objects. It is controlled from a research center on Earth and observes almost continuously. Nevertheless, the telescope has time to complete only a fraction of the many projects proposed by astronomers from around the world. - The Hubble Space Telescope (HST) orbits Earth at an average altitude of km above the surface. In this image, the telescope is viewing toward the upper left. (b) Artist's conception of HST's eventual successor, the James Webb Space Telescope (JWST). JWST will be located in solar orbit almost million miles from Earth, four times as far away as the Moon. It will not have an enclosing tube, thus resembling a radio dish more than a conventional optical telescope. JWST will observe the Universe from behind a multilayered sunscreen larger than a tennis court. (c) Artist's conception of the Herschel infrared space telescope that carried a -m mirror and instruments cooled almost to absolute zero. - Hubble has been visited a number of times by the space shuttle so that astronauts could service its components and install new cameras and other instruments. Thanks to the work of the space shuttle crew who visited in 2009 and accomplished another refurbishment of the telescope's instruments, batteries, and gyroscopes, Hubble will almost certainly last until it can be replaced by the James Webb Space Telescope (JWST), which is expected to be ready in about the year 2018. JWST telescope will be launched into a solar orbit to avoid interference from Earth's strong infrared glow. Its primary mirror is a cluster of beryllium mirror segments that will open in space to form a -m mirror (Figure 6-19b). Telescopes carrying long-wavelength infrared detectors must carry coolant such as liquid helium to chill their optics to near absolute zero temperature ( or ) so that heat radiation from the insides of the telescope and instruments does not blind the detectors. Such observatories have limited lifetimes because the coolant eventually runs out. The European Space Agency's Herschel -meter infrared space telescope (Figure 6-19c), named after the scientist who discovered infrared radiation (Figure 6-4), was launched into solar orbit in 2009 together with the smaller Planck space observatory that studied millimeter-wavelength radiation. Herschel and Planck made important discoveries concerning distant galaxies, star formation, planets orbiting other stars, and the origin of the Universe during their -year lifetimes.
frequency of the wave
- The number of times a given event occurs in a given time; for a wave, the number of cycles that pass the observer in second. - represented by the Greek lowercase letter nu (ν). - If your favorite FM station is on the dial at 89.5 , that means the station's radio waves have a frequency v = 89.5 megahertz (c = 3.00 *10^8 m/s, wavelength = 3.35m)
reflecting telescope structure
- The primary mirrors of reflecting telescopes are much less expensive than lenses because the light reflects off the front surface of the mirror. This means that only the front surface needs to be made with a precise shape and that surface is coated with a highly reflective surface of aluminum or silver. Consequently, the glass of the mirror does not need to be transparent, and the mirror can be supported across its back surface to reduce sagging caused by its own weight. - Most important, reflecting telescopes do not suffer from chromatic aberration because the light does not pass through the glass, so reflection does not depend on wavelength.
light
- The wavelike properties of light produce a rainbow, whereas the particle-like properties are involved in the operation of a digital camera. - used to refer to electromagnetic radiation that humans can see, but visible light is only one among many types of electromagnetic radiation that include X-rays and radio waves - Most forms of light (electromagnetic radiation) are absorbed in Earth's atmosphere. Light can reach Earth's surface only through the visual and radio "windows."
atmospheric windows
- Wavelength region in which Earth's atmosphere is transparent—at visual, infrared, and radio wavelengths.
sound
- a periodically repeating pressure disturbance that moves from source to ear. - requires a medium, meaning a substance such as air, water, or rock to travel through.
radiowaves
- a type of light (electromagnetic radiation) that your radio receiver transforms into sound so you can listen
telescope resolution
- ability to reveal fine detail, depends on the quality of the optics, but it also depends on the diameter of the telescope. Larger telescopes produce smaller diffraction fringes and sharper images. The resolving power of a telescope is the angular separation between two stars that are just barely visible through the telescope as separate images. For telescopes focusing visible light, the resolving power in arc seconds equals 0.113 divided by the diameter of the telescope in meters.
stars in the Southern Hemisphere
- appear to circle around the south celestial pole that lies in the faint constellation of Octans (the Octant), not marked by any bright star.
Star twinkles
- are caused by turbulence in Earth's atmosphere, and a star near the horizon, where you look through more air, will twinkle and blur more than a star overhead.
find sites with the best seeing,
- astronomers carefully select mountains where the airflow is measured to be smooth and not turbulent. Also, the air at high altitude is thin, dry, and more transparent, which is important not only for optical telescopes but also for other types of telescopes.
electromagnetic radiation behavior
- can act as a wave phenomenon—that is, it is associated with a periodically repeating disturbance—a wave—that carries energy - can also behave as a stream of particles
Radio astronomers
- face a problem of radio interference comparable to visible light pollution. Weak radio waves from the cosmos are easily drowned out by human-made radio noise—everything from automobiles with faulty spark plugs to poorly designed communication systems. A few narrow radio bands are reserved for astronomy research, but even those are often contaminated by stray signals. To avoid that noise and have the radio equivalent of a dark sky, astronomers locate radio telescopes as far from civilization as possible. Hidden in mountain valleys or in remote deserts, they are able to study the Universe protected from humanity's radio output.
Galileo
- first person to systematically record observations of celestial objects using a telescope, beginning a little more than years ago in 1610. - Galileo's telescope was a refractor.
2 most important powers of telescope
- light-gathering power and resolving power—depend on the diameter of the telescope that is essentially impossible to change - explains why astronomers describe telescopes by diameter and not by magnification
ground based telescopes
- limited by Earth's atmospheric turbulence and transparency - Most types of electromagnetic radiation arriving here from the Universe—gamma-rays, X-rays, ultraviolet, and much of the infrared—do not reach Earth's surface because they are partly or completely absorbed by Earth's atmosphere. To gather light with those blocked wavelengths, telescopes must go to high altitudes or into space
test resolving power
- measuring the angular distance between two stars that are just barely distinguishable as separate objects - The resolving power in arc seconds of a telescope with primary diameter D that is collecting light of wavelength equals: resolving power =(the conversion between radians and arc seconds) 2.06 *10^5 (wave legth/D) - resolving power (arc seconds) = .113/D
Earths atmosphere
- opaque to most electromagnetic radiation - Gamma-rays and X-rays are absorbed high in Earth's atmosphere, and a layer of ozone at altitudes of about 15 to 30 km ( 10 to 20 mi) absorbs most ultraviolet radiation - Water vapor in the lower atmosphere absorbs most long-wavelength infrared radiation and microwaves. Only visible light, some short-wavelength infrared radiation, and some radio waves reach Earth's surface through wavelength bands called atmospheric windows.
Radiation
- refers to anything that radiates away from a source. - Dangerous high-energy particles emitted from radioactive atoms are also called radiation
which power of a large ground based optical telescope is severely limited by earths atmosphere on a cloudless night
- resolving power
gamma-rays
- shortest - Electromagnetic wave with extremely short wavelength, high frequency, and large photon energy.
refracting telescopes problem
- suffer from a serious optical distortion that limits their use. When light is refracted through glass, shorter-wavelength light bends more than longer wavelengths; so, for example, blue light comes to a focus closer to the lens than does red light - if you focus the eyepiece on the blue image, the other colors are out of focus, and you see a colored blur around the image. If you focus instead on the red image, all the colors except red are blurred, and so on. This color separation is called chromatic aberration. - solution: can grind a telescope lens with two components made of different kinds of glass and thereby bring two different wavelengths to the same focus (Figure 6-7b). That improves the image, but these so-called achromatic lenses are not totally free of chromatic aberration. Even though two colors have been brought together, the others are still out of focus. - more expensive and difficult to build
The focal length
- the distance from the lens or mirror to the point where parallel rays of light from a very distant object come to a focus.
The relationship among the wavelength, frequency, and speed of a wave
- wave length* frequency = speed of wave - The higher the frequency, the shorter the wavelength.
compare the relative light-gathering powers (LGP) of two telescopes A and B
- you can calculate the ratio of the areas of their primaries, which equals the ratio of the primaries' diameters squared - (LGPa)/(LGPb) = (Da/Db)^2 - Because the diameter ratio is squared, even a small increase in diameter produces a relatively large increase in light-gathering power and allows astronomers to study significantly fainter objects. This principle holds not just at visual wavelengths but also for telescopes collecting any kind of radiation.
____ has (have) wavelengths that are shorter than visible light. I. Gamma-rays II. Ultraviolet light III. Infrared radiation IV. X-rays
I, II, & IV
powers of a telescope
-light gathering, resolving
Which of the following let's you conclude that a compact object cannot be a neutron star and that it must be a black hole
If the mass of the compact object is greater than about 3 solar masses
Excited atom
If you move an electron from a lower energy level to a higher energy level, you can call the atom a(n) _____.
The resolving power of an optical telescope with a diameter of 232 cm is
0.05 arc seconds
The resolving power of an optical telescope with a diameter of 232 cm is
0.05 arc seconds.
The average distance from Earth to the Sun is
1 AU
three important points about telescope design and ten new terms that describe optical telescopes and their operation:
1) Conventional-design reflecting telescopes use large, solid, heavy mirrors to focus starlight to a prime focus, or by using a secondary mirror, to a Cassegrain focus (pronounced KASS-uh-grain). Other telescopes have a Newtonian focus or a Schmidt-Cassegrain focus. Icon 2) Telescopes must have a sidereal drive to follow the stars. An equatorial mount with motion around a polar axis is the conventional way to provide that motion. Today, astronomers can build simpler, lighter-weight telescopes on alt-azimuth mounts that depend on computers to move the telescope so that it follows the apparent motion of stars as Earth rotates without having an equatorial mount and polar axis. Icon 3) Active optics, computer control of the shape of a telescope's main mirrors, allows the use of thin, lightweight mirrors—either "floppy" mirrors or segmented mirrors. Reducing the weight of the mirror reduces the weight of the rest of the telescope, making it stronger and less expensive. Also, thin mirrors cool and reach a stable shape faster at nightfall, producing better images during most of the night.
three important points about telescope design
1) conventional-design reflecting telescopes use large, solid, heavy mirrors to focus starlight to a prime focus, or, by using a secondary mirror, to a cassegrain focus. Other telescopes have a newtonian focus or a schmidt-cassegrain focus 2) Telescopes must have a sidereal drive to follow the stars 3) Active optics allows the use of thin, lightweight mirrors
How hot does the core of a star need to be for helium fusion?
1,000,000K
Light can be focused into an image in one of two ways
1. a lens refracts ("bends") light passing through it, or 2. a mirror reflects ("bounces") light from its surface.
What is the ratio of the light gathering power of a telescope with the primary lens of diameter 10 m to a telescope with a primary lens of diameter 1 m
100 to 1
What is the ratio of the light-gathering power of a telescope with a primary lens of diameter 10 m to a telescope with a primary lens of diameter 1 m? 100 to 1 1 to 10 10 to 1 1 to 100
100 to 1
The Oort cloud extends to _____ from the Sun.
100,000 AU
There are ____ nanometers in 1 meter
1x10^-9
The precession of Earth's axis takes about _____ for one cycle.
26,000 years
The precession of Earth's axis takes about _____ for one cycle. 12,000 years 30,000 years 10,000 years 26,000 years
26,000 years
The precession of Earth's axis takes about for one cycle.
26,000 years
Asteroids are commonly found ___ AU from the Sun
3
Except Mercury's orbit, the rest of the planets' orbital planets are inclined by no more than
3.4 degrees
Earth circles the Sun in
365.26 days
Earth circles the sun in ____
365.26 days
The radioactive ages of the moon rocks show that the Moon's surface solidified about
4.4 billion years ago
The Moon must be at least _____ years old.
4.48 billion
Our Sun and its planets were formed about
4.6 Billion years ago
The Kuiper Belt is located just beyond Neptune out to _____.
40 AU or less
The pupil of the human eye is approximately 0.8 cm in diameter when adapted to the dark. The ratio of the light gathering power of a 1.6 m telescope to that of the human eye is ____.
40,000
The shortest wavelength of visible light is
400 nanometers
The shorted wavelength of visable light is
400nm
Violet light has a wavelength of approximately
400nm
What is the wavelength of the shortest wavelength light visible to the human eye?
400nm violet light
The Kuiper Belt is located just beyond Neptune out to _____.
50 AU or more
The Sun rotates with its equator inclined _____ to Earth's orbit.
7.2 degrees
What is the frequency of the shortest wavelength light that can be detected by the average human eye?
7.5´1014 Hz
The longest wavelength of visible light is
700 nanometers
The longest wavelength of visible light is _____. 400 nanometers 900 nanometers 500 nanometers 700 nanometers
700 nanometers Correct. The longest wavelength of visible light is 700 nanometers (nm). The wavelength of visible light ranges between about 400 nm and 700 nm, or, equivalently, 4000 angstroms (Å) and 7000 angstroms (Å)
What is the wavelength of the longest wavelength light that can be seen with the human eye?
700 nm
What is the wavelength of the longest wavelength light visible to the human eye?
700nm red light
Light from the Sun reaches Earth in about_______
8 minutes
A star remains on the main sequence for a time span equal to _____ of its total existence as an energy-generating star.
90 percent
A star remains on the main sequence for a time span equal to _____ of it's total existence as an energy generating star
90%
Coronagraph
A _____ is a telescope designed to capture images of faint objects such as the corona of the Sun that are near relatively bright objects.
Reflecting telescope
A ______ has a main mirror called the primary mirror.
Which of the following is left behind when a star dies? A gray dwarf A black hole A red giant A yellow node
A black hole
Newton concluded that a force from the earth had to act on the moon because
A force is needed to change the direction of the moons motion
reflecting telescope
A has a main mirror called the primary mirror telescope
Total lunar eclipse
A lunar eclipse that occurs when the Moon moves completely into Earth's umbral shadow is called a ______.
Scientific Notation
A method for expressing very large or very small numbers by using powers of 10.
Sometimes when a theory has been refined, tested, and confirmed so often that scientist have great confidence in it, it is called
A natural law
We can't see a new moon in our sky because
A new moon is quite near the Sun in the sky
Planet
A non luminous body that is massive enough to be spherical and to have cleared its orbital path.
Saturn
A planet that is visible to the naked eye from Earth.
radio astronomer disadvantages
A radio astronomer works under two disadvantages relative to optical astronomers: poor resolution and low signal intensity. Recall that the resolving power of a telescope depends on the diameter of the primary lens or mirror but also on the wavelength of the radiation. At very long wavelengths like those of radio waves, the diffraction fringes are quite large. This means that images or maps from individual radio telescopes generally don't show such fine details as are seen in optical images. The second handicap radio astronomers face is the low intensity of the radio signals. You learned previously that the energy of a photon depends on its wavelength. Photons of radio energy have such long wavelengths that their individual energies are quite low. The cosmic radio signals arriving on Earth are astonishingly weak—as little as one-billionth the strength of the signal from a commercial radio station. To get detectable signals focused on the antenna, radio astronomers must build large collecting areas either as single large dishes or by combining arrays of smaller dishes. Even then, because the radio energy from celestial objects is so weak, it must be strongly amplified before it can be measured and recorded.
_____ is the event that occurs when the Moon passes directly between Earth and the Sun, blocking your view of the Sun. A solar eclipse The winter solstice A lunar eclipse The summer solstice
A solar eclipse
______ is the event that occurs when the Moon passes directly between Earth and the sun blocking your view of the sun
A solar eclipse
Stellar assocaition
A stable group of stars that formed together but are not gravitationally bound to one another
Which has the larger light-gathering power?
A telescope of 6 cm diameter and focal length of 100 cm.
Which telescope has the largest light-gathering power among the following telescopes? A telescope of diameter 6 cm and focal length 100 cm A telescope of diameter 2 cm and focal length 100 cm A telescope of diameter 5 cm and focal length 50 cm A telescope of diameter 3 cm and focal length 75 cm
A telescope of diameter 6 cm and focal length 100 cm
On a high mountaintop where the air is thin and steady.
A telescope performs best _____.
OHypothesis
A tentative explanation.
angstrom
A unit of distance; 1 A = 10^-10 m; often used to measure the wavelength of light
nanometer (nm)
A unit of length equal to 10^-9 meters
Heliocentric universe
A(n) ____ is a model of the Universe with the Sun at the center, such as the Copernican universe.
Geocentric Universe
A(n) _____ is a model universe with Earth at the center, such as the Ptolemaic Universe.
Geosynchronous orbit
A(n) _____ is one in which an object Earth has an orbital period
ellipse
A(n) is a closed curve around two points called the foci, such that the total distance from one focus to the curve and back to the other forcus remains constant.
Constellations
All around the worlds, ancient cultures celebrated heroes, Gods, and mythical beats by naming groups of the stars called ______.
Which of the following is associated with the brightness of a star? Apparent brightness Intrinsic brightness Lumunosity All of the Above
All of the above
Which of the following was developed by Newton? Laws of Motion Calculus Gravity All of the above
All of the above
The visible star nearest the Sun, ____, has a parallax of only 0.76 arc second
Alpha Centauri
In the context of luminosity classes,__________is a subgiant (IV).
Altair
Celestial Sphere
An imaginary sphere of very large radius surrounding Earth to which the planets, stars, Sun, and Moon seem to be attached
Weight
An object's _____ is the force that Earth's gravity exerts on the object.
Which of the following is true of ancient constellation?
Ancient constellation boundaries, when they were defined at all, were only approximate.
A(n)__________occurs when the Moon is at its greatest distance from Earth and the Moon is new. annular solar eclipse partial lunar eclipse total solar eclipse total lunar eclipse
Annular Solar Eclipse
Absolute magnitude is...
Apparent magnitude of a star observed from a distance of 10pc
Star names tend to have
Arabic origins
Red dwarfs
Are cool and small with low luminosities
What is the relationship between the angle an object sub tends on the sky and the distance to the object
As object gets closer its angular size increases
Ron is standing near a railroad track. A train is moving toward him at 60 mph, and it blows its horn. What will Ron notice as the train moves past him? As the train approaches, the horn will sound higher in pitch than when the train moves away. The horn will produce a multiple echo effect as the train moves closer to Ron. There will be no change in the pitch of the horn as the train moves past Ron. As the train moves away, the frequency of the horn will be higher than when the train comes closer.
As the train approaches, the horn will sound higher in pitch than when the train moves away.
The Big Dipper is considered to be a(n)
Asterism
Kelvin
Astronomers and physicists express temperature of the Sun and other objects on the ___ temperature scale
The average distance from Earth to the Sun is called the
Astronomical Unit
is the distance between the Earth and the Sun
Astronomical Unit
Jupiter's extensive magnetosphere is responsible for ____ around the planet's magnetic poles
Aurorae
The Sun crosses the celestial equator going southward at the point called the
Autumnal equinox
The Sun is on the celestial equator during the
Autumnal equinox and the vernal equinox
Which of the following stars is a luminous red supergiant and is classified M2 Ia?
Betelgeuse
Which of the following statements is true of an electron?
Binding energy is large when a large amount of energy is needed to pull an electron away from an atom
Meteor
Bit of metal or rock that burns up in the Earth's atmosphere
Meteroid
Bit of metal or rock that is in space
Evening star
By tradition, any planet in the sunset sky is called a(n) ______.
The ______ is an imaginary sphere of very large radius surrounding Earth to which the planets, stars, Sun, and moon seem to be attached
Celestial sphere
A ______ is an electronic device consisting of a large array of light sensitive elements used to record very faint images
Charge-couples device
Epicycle
Claudius Ptolemy created a mathematical model of the Aristotelian Universe in which a planet followed a small circle called the ____ that slid around a larger circle called the deferent.
are small icy bodies that orbit the Sun and produce tails of gas and dust when they approach the Sun.
Comets
Interferometer
Consists of separated telescopes combined o produce a simulated telescope with the resolution of a much larger-diameter telescope
are groups of stars named after heroes,gods, or mythical beasts by ancient cultures
Constellations
How does heat flow in the sun near the surface??
Convection
_____ say that certain things cannot be created out of nothing or vanish into nothing.
Conversation Laws
The problem of the place of Earth was resolved by the
Copernican Revolution
The moons of Jupiter supported the _____ of the universe over the Ptolemaic
Copernican model
The moons of Jupiter supported the__________of the Universe over the Ptolemaic model.
Copernican model
Who first proposed the heliocentric universe?
Copernicus
are circular bulges on Venus up to 1600 mi in diameter bordered by fractures, volcanoes, and lava flows.
Coronae
A _____ is a telescope designed to capture images of faint objects such as the corona of the Sun that are near relatively bright objects
Coronagraph
In the context of supernova explosions, the _____ is a young remnant, only about 960 years old and about 9 ly in diameter.
Crab Nebula
Star cluster NGC 4755, also known as the Jewel Box, is located in the constellation
Crux
Hertzsprung-Russel Diagram
Diagram that organizes star sizes
Very massive stars
Die after only a few million years
Is the process where heavy materials sink towards the core while light materials rise towards the surface of a planet
Differentiation
is the separation of material according to density.
Differentiation
Is the apparent change in the wavelength of radiation caused by relative moton of source and observer
Doppler Effect
Which of the following is true of Copernicus's model of the Universe? Earth was considered to be at the center. Each planet was treated differently. The positions of the planets were predicted accurately. Each planet followed orbits that circled the Sun at the center.
Each planet followed orbits that circled the Sun at the center. Correct. In Copernicus's model, all of the planets were treated the same. They all followed orbits that circled the Sun at the center.
is an example of a Terrestrial planet. Jupiter Saturn Neptune Earth
Earth
____ are similar in size. Mercury and Earth Jupiter and Neptune Earth and Venus Venus and Jupiter
Earth and Venus
_____ are similar in size.
Earth and Venus
365.26 days
Earth circles the Sun in _____.
The observation of the moons of Jupiter by Galileo Galilei suggested that:
Earth could move and keep its moon.
The observation of the moons of Jupiter by Galileo Galilei suggested that: Earth could not move as its moon would be left behind. Earth could move and keep its moon. the Solar System was actually geocentric. the only center of motion was Earth.
Earth could move and keep its moon.
Which of the following was a belief of Copernicus
Earth rotated on its axis
Claudius Ptolemy created an elaborate geometrical and mathematical model to explain details of the observed motions of the planets while assuming: Earth was motionless at the center of the Universe. there were many galaxies in the Universe. the Sun was at the center of the Universe. Earth was part of a galaxy.
Earth was motionless at the center of the Universe.
Claudius Ptolemy created an elaborate geometrical and mathematical model to explain details of the observed motions of the planets while assuming: Earth was motionless at the center of the Universe. there were many galaxies in the Universe. the Sun was at the center of the Universe. Earth was part of a galaxy.
Earth was motionless at the center of the Universe. Correct. Claudius Ptolemy created an elaborate geometrical and mathematical model to explain details of the observed motions of the planets while assuming Earth was motionless at the center of the Universe.
Claudius Ptolemy created an elaborate geometrically and mathematical model to explain details of the observed motions of the planets while assuming
Earth was motionless at the center of the universe
Which of the following was the most imperfect region according to Aristotle's philosophy? The heavens The center of the Sun Earth's surface Earth's center
Earths Center
_____ is a number between 1 and 0 that describes the shape of an ellipse. Acceleration Eccentricity Momentum Mass
Eccentricity Correct. Eccentricity is a number between 1 and 0 that describes the shape of an ellipse. The eccentricity of an ellipse is the distance from one focus to the center of the ellipse divided by the semi-major axis
Throughout the year, the Sun moves eastward among the stars following a line called the ___, the apparent path of the Sun among the stars
Ecliptic
Einstein & Planet Orbits
Einstein's General Relativity predicted that Mercury's elliptical orbit should "precess" at a rate 43 arcsec/century
is pulverized rock scattered by meteorite impacts on a planetary surface.
Ejecta
A(n) _____ is a closed curve around two points called the foci, such that the total distance from one focus to the curve and back to the other focus remains constant. ellipse deferent equant paradigm
Ellipse
An atom can move an electron to a lower energy level by
Emitting a photon of light
Claudius Ptolemy created a mathematical model of the Aristotelian Universe in which a planet followed a small circle called the ____ that slid around a large circle called the deferent
Epicycle
Claudius Ptolemy created a mathematical model of the Aristotelian Universe in which a planet followed a small circle called the _____ that slid around a larger circle called the deferent. heterocycle pericycle epicycle hemicycle
Epicycle
Which of the following is a Kuiper Belt Object that is quite large and has about the same diameter as Pluto but is 27% more massive? Nereid Io Titan Eris
Eris
Ninety percent of all stars are considered
Main sequence stars
is an example of a Terrestrial planet. Jupiter Saturn Mars Neptune
Mars
Mars has very different surface features than Earth. What aspect of mars was MOST important in its developing so differently from Earth
Mars mass
Which of the following planets has the highest uncompressed density? Venus Mars Earth Mercury
Mercury
___ is the closest planet to the Sun.
Mercury
is the closest planet to the Sun.
Mercury
Which of the following have no atmosphere? Venus and Earth Mercury and the Moon Mercury and Mars Mars and Venus
Mercury and the Moon
In astronomical usage all atoms are heavier than helium are referred to as
Metals
____ are reactions that join the nuclei of atoms to form more massive nuclei
Nuclear fusion reactions
_____ are reactions that join the nuclei of atoms to form more massive nuclei.
Nuclear fusion reactions
What is the correct Spectral Class order of star? (HOT TO COLD)
OBAFGKM
Who studied the orbits of planets in Parque with Johannes Kepler as a student?
Tycho
In the context of the electromagnetic spectrum, which of the following forms of electromagnetic radiation has a shorter wavelength than the shortest wavelength of visible light?
Ultraviolet light
In the context of the electromagnetic spectrum, which of the following forms of electromagnetic radiation has shorter wavelength than the shortest wavelength of visible light?
Ultraviolet light
____ is absorbed by ozone in Earths atmosphere that is located between 20 km and 40 km above Earths surface. Therefore, telescopes to observe this radiation must be placed in space.
Ultraviolet radiation
_____ is absorbed by a layer of ozone in Earth's atmosphere at an altitude of about 20 mi above Earth's surface.
Ultraviolet radiation
_____ is absorbed by a layer of ozone in Earth's atmosphere at an altitude of about 20 mi above Earth's surface. Infrared radiation X-ray radiation Ultraviolet radiation Microwave radiation
Ultraviolet radiation Correct. Gamma rays, X-rays, and some radio waves are absorbed high in Earth's atmosphere, and a layer of ozone at an altitude of about 20 mi absorbs almost all ultraviolet radiation. Water vapor in the lower atmosphere absorbs long-wavelength infrared radiation.
The region of a shadow that is totally shaded is known as the
Umbra
Which of the following is a difference between low-mass stars and medium-mass stars?
Unlike medium-mass stars, low-mass stars cannot become giant stars.
In the context of the discovery of Neptune, the existence and location of Neptune were calculated from irregularities in the motion of
Uranus
