Final
vary in both temperature and radius
A Cepheid variable star
a brown dwarf.
A cloud fragment too small to sustain nuclear fusion is:
We see the galaxy the way it was one billion years ago.
A galaxy is at a distance of one billion light years. Which of the following is true?
it generates more heat and its core eventually collapses very suddenly.
A high-mass star dies more violently than a low-mass star because:
short−duration gamma−ray bursts.
A hypernova creates a
large mass
A neutron star's immense gravity is primarily due to is small radius and its
is less luminous.
A nova differs from a supernova in that the nova
d. All of the given options are possible.
A proposed explanation for gamma-ray bursters is a. coalescence of a neutron star binary. b. hypernova-making black holes and bi-polar jets. c. star quakes in magnetars. d. All of the given options are possible.
nova
A surface explosion on a white dwarf, caused by falling matter from the atmosphere of its binary companion, creates what kind of object?
thousands
About how many planets have been found outisde our solar system orbiting other stars?
Solar Corona
Above the transition zone is the Sun's thin, hot upper atmosphere
early in the evolutionary sequence.
According to current theories of galactic evolution, quasars occur
The Universe has no center
According to modern theory, which of the following is true about the location of the center of the Universe?
d. Andromeda
All of the following are clusters of galaxies EXCEPT: a. Coma b. Virgo c. Hydra d. Andromeda
stellar evolution
All stars live and die through a process called
b. all of the above
Angles can be measured by which of the following units? a. I don't know b. all of the above c. degree d. arc second e. arc minute
structure of "clumping" due to filaments and voids.
As we look at larger and larger scales of the visible universe, we find
1000
Astronomers have confirmed the existence of about _______ planets beyond our solar system.
galaxies farther away are moving away from us faster.
Astronomers know the universe is expanding because
solar wind
At a distance of about 15 solar radii, the gas in the corona is hot enough to escape the Sun's gravity, and the corona begins to flow outward as the ___ ___.
comprises over 90% of the entire mass of the universe.
Based on galactic rotation curves and cluster dynamics, we think dark matter
True
Cepheid variables and type I supernova are used as "standard candles" to find distances.
True
Collisions between galaxies is thought to be commonplace.
fainter
Compared with a star of apparent magnitude of -2, a star of apparent magnitude of 0 is
brighter
Compared with a star with a magnitude of +2, a star with a magnitude of -1 is
that it makes up 95% of the universe.
Concerning dark matter and energy, we do know
dark matter not made of protons and neutrons.
Currently, most of the mass of the matter of the universe is believed to consist of
False
Gravity slows the expansion of the universe; dark matter accelerates it.
the Cosmological Principle.
Homogeneity and isotropy, taken as assumptions regarding the structure and evolution of the universe, are known as:
We have no theory capable of addressing this question
How hot was the universe at time zero?
about 11 years
How long does the sunspot cycle last on average?
8
How many planets are in our solar system?
gravitation and pressure
Hydrostatic equilibrium in our Sun is the balance between
most galaxies are moving away from it.
If an alien astronomer in a distant galaxy looks at the galaxies it can see, it will observe that
type I supernova.
If it gains sufficient mass, a white dwarf can become a
average lifetime of a civilization.
If we are optimistic in our assumptions about the development of life and intelligence, then the number of technological civilizations in the galaxy should equal the
c. Europa
In addition to Mars, which Jovian moon shows some promise of life, with a surface not that different from the Arctic Ocean? a. Titan b. Triton c. Europa d. Io
d. all of the above
In comparing our own solar system with others found to date, we find: a. jovians often lie much closer to their suns than ours do. b. that most orbits are less circular than planets around our Sun. c. multiple planets are found in some systems. Incorrect d. all of the above
if the beam sweeps across us, we will detect a pulse of radiation.
In the Lighthouse model:
Standard Solar Model
Model that best fits the observed properties of the Sun
radio wavelengths.
Most SETI searches are done at
Chromosphere
Most of the absorption lines seen in the solar spectrum are produced here
dark matter out in the Halo
Most of the mass of the Milky Way seems to exist in the form of
coronal holes
Most of the solar wind flows outward from low density regions of the corona called ___ ___.
in a cluster of stars.
Most stars, probably all stars, formed...
age
Noting the turnoff mass in a star cluster allows you to determine its
create elements up to and including carbon
Nuclear fusion in the Sun will
strong nuclear force
Nuclei are held together by ___ ___ ___.
a super massive black hole
The object located at the center of the Galaxy is believed to be:
halo
The oldest stars in the galaxy are located in the
Main sequence, red giant, planetary nebula, white dwarf
The order of evolutionary stages of a star like the Sun would be?
brown dwarf, white dwarf, neutron star, black hole
The order of mass from lowest to highest is
Henrietta Leavitt
The period-luminosity relation was discovered in 1908 by
the fusion of hydrogen into helium
The primary source of the Sun's energy is...
we detect fewer solar neutrinos than we expect.
The solar neutrino problem is that...
O, B, A, F, G, K, M
The spectral class from highest temperature to lower temperature is:
spiral barred
The structure of our Milky Way is most similar to
T Tauri phase.
Stage 4 of star formation is when the object can exhibit violent surface activity producing extremely strong protostellar winds. This phase is also called the...
Star A has a larger radius.
Star A and star B both have the same temperature, but star A has a larger luminosity. What can you infer about the stars?
True
Stars form from a collapsing cloud that fragments into smaller and smaller pieces.
magnetic field rises and falls.
Sunspot cycle occurs as the...
magnetism
Sunspots are regions of intense ___.
True
Supermassive black holes may play a role in the formation and evolution of galaxies.
solar cycle
The 22-year cycle that results when the direction of the field is taken into account is called the solar cycle.
hydrogen and helium, but nothing else.
The Big Bang formed
the upper mass limit for a white dwarf.
The Chandrasekhar Limit is
noting the gravitational influence of a planet on the star's motion
The Doppler shift method finds extrasolar planets by
the number of technical civilizations in our galaxy presently
The Drake equation calculates N. What is N?
225 million years.
The Galactic Year, the time for our solar system to orbit the Galaxy, is about
luminosity
The Hertzsprung-Russell Diagram plots ________ against the spectral type or temperature.
is, in terms of the star's gravity, its "zone of influence."
The Roche lobe of a star in a binary star system...
rotation
The Tully-Fisher relation exists between the galaxy's luminosity and its
ten parsecs.
The absolute magnitude of a star is its brightness as seen from a distance of:
Solar constant
The amount of solar energy reaching a 1 m^2 at the top of Earth's atmosphere each second
red giant branch
The asymptotic giant branch is similar to the
an astronomical unit
The average distance between the Earth and the Sun is called
the inflationary epoch.
The best answer to both the flatness and horizon problems is
does not exist anywhere in space.
The center of the universe
type I supernovae
The critical evidence for cosmic acceleration in 1998 came from two teams of astronomers, both observing:
it was was experimental verification of a prediction from the Big Bang theory.
The discovery of the cosmic microwave background was important because
Granulation
The effect of the solar convection zone can be seen on the surface in the form of ___.
Frank Drake
The equation that estimates the factors which determine how many technological civilizations are present in our galaxy was developed by _______.
increasing
The expansion rate of the Universe is
True
The first planet directly imaged was Fomalhalt b.
Pioneer 10
The first probe carrying mankind's message to alien civilizations was:
the longer ago it existed.
The further away a galaxy is
find a planet like Earth
The goal of the Kepler mission is to
temperatures are suitable for planets to have liquid water.
The habitable zone is the area around a star where:
during a type II supernova explosion.
The heaviest nuclei of all are formed
mass.
The main factor that influences where a star appears on the main sequence is
Core
The main interior region of the Sun where nuclear reactions generate energy.
flares
The more intense ___ are violent surface explosions that blast particles and radiation into interplanetary space.
Nuclear fusion
The sun generates energy by converting hydrogen to helium in its cor by the process of nuclear fusion.
perform an experiment
The third step in the scientific method is
Luminosity
The total amount of energy radiated from the solar surface per second.
the interior structure of the Sun.
The vibrations of the Sun reveal information about...
Jovian Planets
They are usually primarily composed of low-boiling-point materials, rather than rock or other solid matter, but massive solid planets can also exist.
Novae
To which of these phenomena are X-ray busters most similar?
cooled off white dwarfs that no longer glow visibly
What are black dwarfs?
found in the plane of the galaxy
What are the characteristics of an open cluster of stars?
luminosity, mass, and radius
What are the intrinsic properties of stars?
Nothing
What can we detect from matter that has crossed an event horizon?
The horizon problem in that the microwave background is almost too isotropic
What did the cosmic microwave background tell cosmologists about the early universe?
amino acids
What important molecules of life did Miller and Urey brew up?
There is no longer nuclear fusion in its core.
What inevitably forces a star like the Sun to evolve away from being a main sequence star?
the ejected envelope of a red giant surrounding a stellar core remnant
What is a planetary nebula?
The corona is much hotter than layers of the Sun that are closer to the solar interior
What is it about the Sun's corona that astronomers don't understand?
high temperatures
What is needed for nuclear fusion to occur?
Radiation pressure from nuclear fusion
What is the force that keeps a main sequence star from collapsing on itself?
The universe will expand forever
What is the meaning of a "open" universe?
Hydrogen
What is the most abundant element in the Sun?
a red giant, a nova, a type I supernova, a type II supernova
What is the order of visual luminosity from least to most luminous?
13.8 billion years
What is the presently accepted value for the age of the universe?
Mass
What is the single most important characteristic in determining how long a star lives?
The arms orbit the center.
What is true of spiral galaxies?
It is the remnant of a supernova observed by humans.
What makes the Crab Nebula supernova remnant unusual as a supernova remnant?
the galactic disk
What part of the galaxy is the solar system located?
They believed that the Milky Way was the entire universe.
What perception of the Milky Way Galaxy did astronomers have in 1900?
The collapse of part of an interstellar cloud of gas and dust.
What process is reponsible for the formation of a new star?
d. all of the above
What triggers might have made part of an interstellar cloud begin to contract? a. supernova b. density waves c. shockwave d. all of the above
it contains amino acids
What unusual discovery was made about the Murchison Meteorite?
a theory incorporating all four forces
What would help scientists probe the period from zero time to 10-43 second?
proton-proton chain
When four protons are converted to a helium nucleus in the ___ ___ ___, some mass is lost.
New
When the Moon appears to cover the Sun (a solar eclipse), the Moon must be in what phase?
near the end of the 20th century
When was the first confirmed exoplanet discovered?
we can, by the drop in light, find the planet's size, mass, and density.
When we see an extra-solar planet transit its star
Convection zone
Where the Sun's matter is in constant convective motion.
Radiation zone
Where the energy travels outward in the form of electromagnetic radiation
Galileo
Which astronomer's observations with the telescope showed that the Earth is not the center of the solar system?
fusion of hydrogen atoms into helium atoms
Which event marks the birth of a star?
tightly bound
Which is characteristic of globular star clusters?
e. all are methods for detecting exoplanets
Which is not a method for detecting exoplanets? a. direct imaging b. radial velocity c. transit d. microlensing e. all are methods for detecting exoplanets
in the disk, and about half way out from the center
Which is the correct description for the Sun's location in the Galaxy?
Earth, Venus, Mars, Mercury
Which of the following are the terrestrial planets?
sizes of HII regions
Which of the following is not a way to determine distance to objects in astronomy? Select one:
red dwarfs
Which of the following is the most common type of star?
a. speed
Which of the following is the same for an electromagnetic wave in space? a. speed b. I don't know c. frequency d. wavelength e. energy
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
Which of the following lists is correctly arranged in order from closest to furthest from the Sun?
The greater the distance to a galaxy, the greater its redshift.
Which of the following paraphrases Hubble Law?
d. O
Which of the following spectral class for stars corresponds to the hottest star? a. A b. B c. G d. O
Jovians have a higher density than the terrestrials.
Which of the following statements is NOT true in the way that terrestrial and Jovian planets differ?
coronal mass ejections
Which of these active regions have the most energy?
The two types are both closely related to evolution of white dwarfs.
Which of these is NOT true about supernovae?
planetary nebula
Which of these will the Sun probably become in the very distant future?
It includes the Abell 1689 cluster.
Which statement about the Local Group is false?
Big Bang Theory
Which theory of the universe is accepted by most scientists?
There are likely to be an above average number of flares and prominences.
While observing the Sun, you not a large number of sunspots. What can you conclude?
electron degeneracy.
White dwarfs are kept from collapsing inward by...
Jocelyn Bell
Who discovered the first pulsar in 1967?
Penzias and Wilson
Who is credited with the discovery of the cosmic microwave background radiation:
Stars in clusters have the same age, similar composition, and are at the same distance away.
Why are star clusters almost ideal "laboratories" for stellar studies?
Their lifetime is too short
Why do we feel type O and B stars are poor candidates for extraterrestrial life?
d. All of the above.
Why was Herschel's strategy for mapping our Galaxy flawed? a. He assumed all stars have the same brightness. b. He did not account for extinction. c. He assumed the Sun was in the center. d. All of the above.
Edwin Hubble
______ proved that the spiral nebulae were other galaxies.
Guth
_______ is responsible for the inflation theory, which is a modification to the big bang.
Star
a glowing ball of gas held together by its own gravity and powered by nuclear fusion at its center
pulsar
a highly magnetized, rotating neutron star or white dwarf, that emits a beam of electromagnetic radiation.
solar constant
a measure of flux density, is the mean solar electromagnetic radiation (the solar irradiance) per unit area that would be incident on a plane perpendicular to the rays, at a distance of one astronomical unit (AU) from the Sun (roughly the mean distance from the Sun to the Earth).
transition zone
above the chromosphere, the temp increases from a few thousand to around a million kelvins.
Sunspots
are Earth-sized regions on the solar surface that are a little cooler than the surrounding photosphere.
Galactic halo
contains the oldest stars
Galactic bulge
contains the super massive black hole at the center
Neutrino oscillations
convert some neutrinos to other (undetected) particles en route from the Sun to Earth.
Galactic disk
has spiral arms
Coronal mass ejecions
huge blobs of magnetized gas excaping into interplanetary space.
Photosphere
is the region at the Dun's surface from which virtually all the visible light is emitted.
Prominences
looplike or sheetlike structures produced when hot gas ejected by activity on the solar surface interacts with the Sun;s magnetic field.
Neutrinos
nearly massless particles that are produce in the proton-proton chain and escape from the Sun. They interact via the weak nuclear force.
Law of conservation of mass and energy
requires that this mass appear as energy, eventually resulting in the light we see.
Terrestrial Planets
telluric planet, or rocky planet is a planet that is composed primarily of silicate rocks or metals.
Helioseismology
the study of vibrations of the solar surface caused by pressure waves in the interior provides further insight into the Sun's structure
extremophiles
Recently discovered organisms that create their energy through chemical reactions (chemosynthesis instead of photosynthesis) are:
active regions
Solar activity tends to be concentrated in ___ ___ associated with groups of sunspots.
True
From what astronomers can see, the geometry of the universe if flat.
nuclear fusion (combining of light elements to heavy)
From where does a star's energy, including the Sun's, come?
merging to form larger galaxies.
Galaxies evolve by
Radiation zone, convection zone, photosphere, chromosphere
From inside out, put the structure of the Sun in correct order: photosphere, chromosphere, radiation zone, convection zone
True
For active galaxies, the actual source of the energy emitted is accretion onto a supermassive black hole in the galactic nucleus.
supergranulation
Lower levels in the convection zone also leave their mark on the photosphere in the form of larger transient patterns called ___.
hydrogen and helium.
Nearly all the elements found in nature were formed inside stars, except for
neutron degeneracy
Neutron stars kept from collapsing inward by
an accretion disk of infalling matter
Not only does the central engine of active galaxies and quasars require a black hole, but also ________ to provide the radiate energy.
at the top right.
On the H-R diagram, red supergiants like Betelgeuse lie
...about the middle of the main sequence
On the H-R diagram, the Sun lies...
Earth, Solar System, Milky Way, Local Group, Virgo Supercluster
Order the following from smaller scale to larger.
Planck, GUT, Quark, Lepton, Nuclear
Order the radiation era epochs in correct order from the big bang.
the gravitational force
Present day Grand Unified Theory unifies all the fundamental forces except
particulate, galactic, stellar, planetary, chemical, biological, cultural
Put the seven phases of cosmic evolution in order.