astronomy final
This diagram represents a star with an orbiting planet that, as seen from Earth, periodically transits across the face of the star and disappears behind the star. At which point would the system appear brightest?
1
this diagram represents an edge-on view of our milky way galaxy. which object is located near the Sun's position in the galaxy?
1
Which feature in this photo of the full Moon is one of the lunar Maria? how do you know?
1... the smooth, dark regions are the lunar Maria
use the parallax formula (d=1/p) to calculate the distance D (in parsec) to Alpha Centauri who is parallax angle P is 0.742 arc sec
1.3
The labeled transitions (A—E) represent an electron moving between energy levels in hydrogen. The transition from level 3 to level 2 generates what is known as the H-alpha line and is among the most important lines in astronomy. The photon corresponding to this transition has a wavelength of 656 nm placing it firmly in the red part of the visible spectrum. What is the energy of this photon?
1.9 eV
how many times stronger is the max energy of a supernova (10^46) compared to the annual output of the sun. (10^34)
10^12
Suppose there are 1,000 civilizations broadcasting radio signals in the Milky Way right now. On average, how many stars would we have to search before we would expect to hear a signal? Assume there are 100 billion stars in our Galaxy.
10^8
This diagram represents the conveyor-like action of plate tectonics on Earth. Which numbered position represents a place where new crust is emerging on the seafloor?
2
this diagram represents an edge-on view of our milky way galaxy. which object is located near a 4-million solar-mass black hole?
2
this graph shows how the apparent brightness of the eclipsing binary system changes with time. which of the four labeled regions represents the system at a time the one star is eclipsing the other?
2 and 4
The quasar 3C 273 is moving away from us at nearly 16% the speed of light, i.e. its velocity (v) is 48,000 km/s. Using the Hubble-Lemaître Law: v=H0 x d where H0 = 22 km/s/Mly, find the distance (d) to this galaxy.
2,200 Mly
use the parallax formula (d=1/p) to calculate the distance D (in parsec) to Procyon who is parallax angle P is 0.286 arc sec
3.5
The graph shows how a star's orbital speed varies with time due to the gravitational tug of an orbiting planet. Based on these data, what is the planet's orbital period (in days)?
4
this diagram represents an edge-on view of our milky way galaxy. which object is located in the halo of the galaxy?
4
how many times stronger is 2.5x10^16 compared to 5x10^15?
5
how many liters of oil (1.2x10^7) would be needed if the United States obtained all its energy from oil (total energy: 10^20)
8.3 x 10^12
The data in this diagram represent the measured speeds and distances of various galaxies, and the solid line represents a best fit to these data. The trend indicated by the solid line is known as:
Hubble's Law
what does this graph show
It shows calculations indicating that the temperature of the universe began quite high but is now quite low.
Which lists the jovian planets in order of increasing distance from the Sun?
Jupiter, saturn, uranus, neptune
which kind of star is most likely to be part of the spheroidal population of a galaxy?
M star
This photo was taken on the surface of:
Mars (The give-aways include the rover in the foreground, red rocks, and the yellowish atmosphere)
The asteroid belt lies between the orbits of
Mars and Jupiter
This photo was taken from orbit around some planet. What planet is it, and how do you know?
Mars, because we see dried up riverbeds
Why does Neptune appear blue and Jupiter red?
Methane in Neptune's atmosphere absorbs red light.
What does this figure tell us?
The current level of carbon dioxide in our atmosphere is higher than it has been at any time during the past 800,000 years.
This figure summarizes the geological histories of the terrestrial worlds. Based on this figure, what can you conclude?
The most important factor in a planet's geological history is its size.
What is the significance of the yellow lines on this map of Earth?
They represent boundaries between the plates that make up Earth's lithosphere.
suppose you visit the moon
Your mass would be the same as on Earth, but your weight would be different.
which of the stars has the greatest surface temperature
a 30 solar mass main sequence star
which of these binary systems is most likely to contain a black hole
a binary containing an O star and another object of equal mass
what is the current temperature of the universe
a few thousand degrees
this photo shows an object located. in the halo of our Milky Way. what kind of object is it
a globular cluster of stars
How large an object causes a typical shooting star?
a grain of sand or a small pebble
a photograph of a cluster of galaxies shows distorted images of galaxies that lie behind it at greater distances. this is an example of what astronomers call
a gravitational lens
The figure to the right shows a "slice of the universe" from the Sloan Digital Sky Survey. What is the Sloan Great Wall (indicated by the arrow)?
a huge collection of galaxies extending a billion lt-yrs in length
Consider a spinning disk of pizza dough. What would the rotation curve () for the spinning dough look like?
a linear graph going up from left to right
what does this diagram represent
a particle and antiparticle colliding and converting all their mass into photons
which of the following possible types of universe would not expand forever
a recollapsing universe
which of the stars does not have fusion occur in its core
a red giant
to explain the fact of evolution, we rely on the theory of natural selection which is
a scientific theory, meaning that it is backed by extensive evidence
This Hubble Space Telescope photo shows a planetary nebula. What is the white dot in the center (indicated by the arrow)?
a white dwarf
Which kind of object is the best standard candle for measuring distances to extremely distant galaxies?
a white dwarf supernova
If you looked at the field of view seen in this Hubble Space telescope with your naked eye, about how big would it appear in the sky?
about the size of an eye of a need held at arms length against the sky
the bright object in this photo is a quasar in the center of a distant galaxy. according to current understanding, about how big is the source of the bright light?
about the size of our solar system
upward transitions e^- gained energy by absorbing a photon
absorption line
These diagrams represent four possible models for the Universe. Each model shows how the size of the observable Universe changes with time. Which model presumes the existence of some type of dark energy in the universe?
accelerating universe
Which of these galaxies would you most likely find at the center of a large cluster of galaxies?
an ellipitical galaxy
this photo shows the famous Crab Nebula. what is it?
an expanding cloud of remains from a star that died in a supernova
a brown dwarf is
an object not quite massive enough to be a star
what do we need to measure in order to determine a stars luminosity?
apparent brightness and distance
Which of the following is a legitimate conclusion from the graph shown, which is based on analysis of Kepler results?
atleast about 15% of stars have a plant similar to earth's size
The labeled transitions (A—E) represent an electron moving between energy levels in hydrogen. Which transition represents an atom that absorbs a photon with 10.2 eV of energy?
b
Why do virtually all the galaxies in the universe appear to be moving away from our own?
because expansion causes all galaxies to move away from nearly all others
You observe a star and measure a spectral line at a wavelength of 652 nm. Normally, this spectral line should appear at a wavelength of 656 nm. Given this information, the star is:
blue shifted
catabolism refers to chemical reactions that
break down structure
The labeled transitions (A—E) represent an electron moving between energy levels in hydrogen. Which transition represents an atom that emits a photon with 10.2 eV of energy?
c
Which of the following correctly lists our "cosmic address" from small to large? a. Earth, Local Group, Milky Way, Solar System, Local Supercluster, Universe. b. Earth, Solar System, Local Group, Local Supercluster, Milky Way, Universe. c. Earth, Solar System, Milky Way, Local Group, Local Supercluster, Universe d. Earth, Solar System, Local Group, Milky Way, Local Supercluster, Universe.
c. Earth, Solar System, Milky Way, Local Group, Local Supercluster, Universe
A car is accelerating when it is: a. on a ferry cruising at 20 knots. b. traveling on a straight, uphill road at 20 mph. c. going around a circular track at 20 mph. d. traveling on a straight, flat road at 20 mph.
c. going around a circular track at 20 mph
What causes the cycle of solar activity?
changes in the organization of the suns magnetic field
The set of spectral lines that we see in a star's spectrum depends on the star's:
chemical composition
what is this picture of
cluster of galaxies
stars can form most easily in clouds that are
cold and dense
What are the dark blobs (indicated by the red arrows) in this photograph ?
cold, dense molecular clouds in which stars are forming
Which lists the major steps of Solar System formation in the correct order?
collapse, condensation, accretion
when a proton and an antiproton collide, they
convert into two photons
The labeled transitions (A—E) represent an electron moving between energy levels in hydrogen. Which transition, as shown, is not possible?
d
Which of the following is not true about a scientific theory? a. Even the strongest theories can never be proved true beyond all doubt. b. A theory must explain a wide range of observations or experiments. c. A theory is stronger than a hypothesis and weaker than a law. d. A theory is essentially an educated guess.
d. a theory is essentially an educated guess
The labeled transitions (A—E) represent an electron moving between energy levels in hydrogen. Which transition represents an electron that is breaking free of the atom?
e
what do emission lines tell us and what do they look like
electron drops to a lower energy level by emitting a photon and they are shown as a black gap or black line
what do absorption lines tell us and what do they look like
electron rises to a higher energy level and they are shown as a more prominent line
downward transition e^- lost energy by releasing a photon
emission line
The labeled transitions (A—E) represent an electron moving between energy levels in hydrogen. What does transition A represent?
emission of a photon with 12.1 eV of energy
where do gamma ray burst tend to come from
extremely distant galaxies
To make a rocket turn left, you need to:
fire an engine that shoots out gas to the right
in this diagram, red balls represent protons and gray balls represent neutrons. what reaction is being shown
fusion of helium into carbon
this photo shows the Large Magellanic Cloud (LMC). which of the following statements about LMC is not true?
galaxies similar to the LMC are extremely rare
The gravitational potential energy of a contracting interstellar cloud:
gradually transforms into other forms of energy
Notice the blue ovals (such as those indicated by the arrows) in this image of a galaxy cluster. The oval structures are not really located where they appear to be, but instead are multiple images of a single galaxy that lies directly behind the cluster. What do we call the process that creates these multiple images?
gravitational lensing
the primary source of a quasar's energy is
gravitational potential energy
suppose a particular star has a core that is undergoing multiple stages of Fusion simultaneously to give it to structure shown in the diagram. based on you understanding of stellar lives the mass of the star is
greater than 8 times the mass of the sun
anabolism refers to chemical reactions that
grow larger structures
at the center of the sun, fusion converts hydrogen into...
helium, photons, and neutrinos
Compared to red light, blue light has higher frequency and
higher energy and shorter wavelength
The composition of the Solar nebula was 98%:
hydrogen and helium
according to diagram, how much more abundant is hydrogen in the universe than nitrogen?
hydrogen is about 10,000 times as abundant as nitrogen
When we say that a planet has a highly eccentric orbit, we mean that:
in some parts of its orbit it is closer to the sun
where are most of the Milky Way's globular clusters?
in the halo
The top panorama shows our view of the Milky Way in all directions as it appears in visible light. The bottom panorama shows the same view but in a different wavelength of light. What wavelength band are we seeing in the bottom photo?
infrared light, because the dust that appears dark I the visible light photo glows in infrared light
This star map shows stars as we see them in our sky from Earth. Larger dots represent brighter stars, and a few of the brightest stars are identified. From this view alone, what can you conclude about Sirius (the largest dot)?
it has the greatest apparent brightness of a star in this region of the sky
in this photo of a spiral galaxy or an elliptical galaxy, and how do you know
it is a spiral galley, because we can see a dusty disk going across the center
this photo shows gas associated with a protostar. what is this gas doing?
it is flowing outward in tow opposite directions from the protostar
This graph shows the brightness of a star over the course of a transit. Which of the following do we learn about the planet?
it is large enough to block about 2.5% of the star's light
How does the habitable zone around a star of spectral type G compare to that around a star of spectral type M?
it is larger
The data points on this graph represent the measured spectrum of the cosmic microwave background, while the solid curve represents a theoretically calculated thermal radiation spectrum for a temperature of 2.73 K. What is the significance of the near-perfect match between the data and the theoretical spectrum?
it shows that the cosmic microwave background has a thermal radiation spectrum, just as the Big Bang theory predicts it should
what happens to the core of a high mass star immediately after in runs out of hydrogen?
it shrinks and heats up
Each dot on this graph represents an individual Cepheid variable star. Which of the following is true for a Cepheid that is 10,000 times as luminous as the Sun?
it varies gradually in brightness, with a peak in brightness about every 30 days
the arrow in the photo on the left points to the star that we see as a supernova in the photo on the right. what can we conclude about this star?
it was a high-mass with at least 8 times the mass of the sun
The labeled transitions (A—E) represent an electron moving between energy levels in hydrogen. How does the wavelength of the photon involved in transition A compare to that of the wavelength in transition C?
it would be shorter
what would happen to a neutron star who accretion disk orbits in the same direction as the neutrons star's spin
it's spin would speed up
This figure shows observations over more than a decade that have allowed us to determine the orbits of several stars around Sgr A* (the central object). What can we learn about Sgr A* by analyzing these orbits?
its mass
according to current understand, the key requirement for life is
liquid water
what is the main idea captured by this graph
low-mass stars are much more common than higher-mass stars
homeostasis refers to chemical reactions that
maintain a constant level of chemicals
Two stars that are in the same constellation:
may be far from each other in space.
This graph is made from data measurements of the cosmic microwave background (CMB) and a model based on the hypothesis of inflation. What does it show?
measurements of the separation between regions of different temperature (in the CMB) agree with predictions made by hypothesis of inflation
You observe a star and measure a spectral line at a wavelength of 652 nm. Normally, this spectral line should appear at a wavelength of 656 nm. Given this information, the star is: blue shifted, meaning it is...
moving towards us
which of these pieces of evidence supports the idea that inflation really happened
observations of the cosmic microwave background that indicate large-scale homogeneity in the universe
If Earth were twice as far from the Sun, the force of gravity attracting Earth to the Sun would be:
one-quarter as strong
Some jovian planets give off more energy than they receive because of:
ongoing contraction
solar energy leaves the core of the sun in the form of
photons
which of these layers of the sun is the coolest?
photosphere
Each dot on this graph represents an extrasolar planet detected by the Kepler mission. Notice the blue rectangle at the right; what does this region represent?
planets with the longest orbital periods
In winter, Earth's axis points towards the star Polaris. In summer, the axis points towards:
polaris
These diagrams represent four possible models for the Universe. Each model shows how the size of the observable Universe changes with time. Which model gives the Universe the youngest age at present?
recollapsing universe
this photo shows an object located in the halo of our milky way. there are many bright red dots in the photograph. what are they?
red giant stars
based on this diagram, "red sequence" galaxies are ________ than "blue cloud" galaxies?
redder and more luminous
based on current evidence, which is considered a likely candidate for the majority of the dark matter in galaxies
subatomic particles that we have not yet detected
the time corresponding the point at the upper left of the diagonal line represents
the Plank time
the time corresponding to the point to the lower right of the diagonal line represents
the age of the universe today
This image shows a colliding pair of galaxy clusters known together as the Bullet Cluster. The blue region represents a map of the cluster's dark matter. How was this blue map made?
the blue region was inferred from studies of how the cluster causes gravitational lensing of objects located behind it
all the stars in this photo are at about the same distance from Earth (some 25,000 light years away). which stars in this. picture are the largest in size (radius).
the bright red stars
this photograph shows an interstellar bubble about 10 light-years in diameter. if you could photograph this same region about 100 years from now, how would you expect it to look different?
the bubble will be slightly larger
This graph shows how the average distances between galaxies changes with time in the four models for the universe and also shows data points measured from white dwarf supernovae. Which of the following statements best describes what the data are telling us?
the data indicate that wee live in an accelerating universe
this sequence of painting represent the formation of the Milky Way. what law of nature explains why the galley began to rotate rapidly and flatten out as it decreased in size
the law of conservation of angular momentum
how would aa flashing yellow light appear as it fell into a black hole
the light would be redshifted and would flash more slowly
Study this graph, focusing on the red curve and reddish horizontal swath. Which statement that follows correctly interprets what the graph shows?
the measured abundance of deuterium agrees with the theoretically predicted abundance only if we make the prediction with a model of the universe in which ordinary matter makes up about 5% of the critical density
we measure the mass of the black hole at the galactic center from
the orbits of stars in the galactic center
this famous image from the Hubble space telescope shows what is sometimes called the pillars of creation, which best describes what it shows?
the pillars are clouds of gas and dust in which many new stars are forming, the edges of the pillars are sculpted by ultraviolet radiation from stars outside the pillars
The graph shows how a star's orbital speed varies with time due to the gravitational tug of an orbiting planet. These data were obtained by measuring:
the precise wavelengths of spectral lines in the spectrum of the star
notice the well-define spiral arms in this photograph of the galaxy M51. what makes the spiral arms so much brighter than regions between the arms?
the presence of many massive young stars in the spiral arms
This image combines a visible light view of the galaxy Hercules A with an image showing radio wave emission (the reddish colors) in its vicinity. The likely explanation for the two huge clumps of radio emission far to either side of the visible galaxy is:
the radio emission comes from gas shot out into space by jets powered by a supermassive black hole in the galactic center
why do some of the bright stars. (such as the one indicated by the arrow) in this photo have cross-shaped spikes over them?
the spike are an artifact of photography through a telescope
what pieces of information would you need in order to measure the masses of stars in an eclipsing binary system
the time between eclipses and the average distance between stars
what can astronomers learn by carefully measuring the distortions in this image
the total mass of cluster
which of the following does inflation help to explain
the uniformity of the cosmic microwave background
The fact that nearly all galaxies are moving away from us, with more distant ones moving faster, helped us to conclude that...
the universe is expanding
Which of these options is the best explanation for why the night sky is dark?
the universe is not infinite in space
This image shows two tall volcanoes on Venus. Why is it yellow?
the yellow color is arbitrary, since this image was created with radar data rather than visible light
The graph above shows the rotation curves (orbital velocity of stars vs. distance from the center) of four different spiral galaxies. Based on these curves, what do all four galaxies have in common?
their most distant stars all orbit at about the same speed as stars located about 50,000 lt-yrs from their centers
which of the following is not implied by this diagram
there are six distinct forces known to operate in the universe and a seventh force called the "super force" might also exist
why do sunspots appear darker than their surroundings?
they are cooler than their surrounding
this diagram shows several stages in a computer simulation of a collision between two galaxies. what happens?
two spiral galaxies merge to become an elliptical galaxy surrounded by debris
this photograph shows X-ray emission from supernova remnant. what is the source of the X-rays?
very hot gas expanding outward from the site of a supernova
Dark matter is inferred to exist because:
we can observe it gravitational influence on visible matter and on light
The star Betelgeuse is about 600 light-years away. If it explodes tonight:
we won't know until about 600 years from now
what would you be most likely to find if you returned to solar system in 10 billion years
white dwarfs
fossil evidence suggests that life arose on earth
within a few hundred million years after earth formed
