ASTRON 60281

subject Type Homework Help
subject Pages 25
subject Words 3083
subject Authors Eric Chaisson, Steve McMillan

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The majority of dark matter is normal protons and neutrons.
All modern large optical telescopes are refractors.
Radio astronomy can only be done from up in space, due to our ionosphere.
Comets are not actually members of the solar system, but have been captured by the
Sun.
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All four jovian planets are thought to have cores larger than Earth.
Two stars have the same absolute magnitude, but one lies twice as far from Earth as the
other. It will appear half as bright.
The Earth's atmosphere is the major factor limiting the use of ground-based radio
telescopes.
Deuterium abundance suggests that normal matter makes up only 3-4% of the critical
density.
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Most galaxies are isolated in space.
Two of the Galilean moons of Jupiter are the size of Mercury, and the two others are
about as big as our own Moon.
In its early stages, the Milky Way was probably a quasar.
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Galactic collisions mostly involve interactions between gas and dust clouds rather than
individual stars.
Uranus' rotation axis is tipped over 98 degrees, so its magnetosphere is tipped over the
same amount.
Cosmic inflation continues today in the cosmological red shifts and dark energy.
Of all the Galilean satellites, the surface of Europa is the youngest in age.
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Compared to the interstellar medium, the gases in a planetary nebula will be richer in
helium and carbon.
The Oort Cloud lies closer to the Sun than the Kuiper Belt.
The Local Group of galaxies spans about 30 million light years in diameter.
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Compared to Earth, Venus spins very rapidly on its axis.
While most pulsars slow down over time, millisecond pulsars spin faster due to mass
transfer from a close companion.
The greater the mass of the foreground cluster of galaxies, the more warped the images
of the distant galaxies are when they undergo gravitational lensing.
Young open clusters contain a lot of hot, young blue-white stars.
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Most of the mass of our galaxy lies between Earth and the Galactic center.
All four jovian planets spin faster than any of the terrestrials.
Redshift surveys are designed to find which galaxies are oldest and youngest.
Winds on Mars give rise to planet-wide dust storms.
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The globular star clusters are the most obvious examples of Population II around us.
Spectroscopic parallax is more accurate than trigonometric parallax for nearby stars.
Over 20,000 stars are visible to the naked eye on the darkest, clearest nights.
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Core-dominated radio galaxies and radio galaxies with lobes are very similar in reality;
we view themfrom different angles, which accounts for their different appearances.
Carbonaceous asteroids contain fragile organic molecules.
About 90% of the star's total life is spent on the main sequence.
Of all the stars in the sky, Barnard's star, the next closest beyond Alpha Centauri,
appears to move the fastest.
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The prolonged period of few sunspots between 1645 and 1715 is known at the Maunder
Minimum.
Of the billions of possible combinations of atoms into organic molecules, only about
1500 actually occur.
Constellations are close clusters of stars, all at about the same distance from the Sun.
Which of these objects have not been found in the Galactic Halo?
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A) RR Lyrae variables
B) Cepheid variables
C) emission nebulae
D) Population II stars
E) globular clusters
What is the meaning of a "closed" universe?
A) The universe will expand forever.
B) The universe will someday stop expanding and start to collapse.
C) The universe will stop expanding in an infinite amount of time.
D) The universe is in a steady-state.
E) The universe will disappear into a white hole in time.
In a hypernova, a very energetic supernova creates a
A) very visible supernova remnant.
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B) millisecond pulsar.
C) set of planets to orbit their neutron star host.
D) black hole.
E) white dwarf and its planetary nebula.
Alternating zones of rising and sinking gas in Jupiter's atmosphere
A) create light and dark bands.
B) cause Jupiter's magnetic field to ripple.
C) produced the ring system discovered by Voyager.
D) generate magnetic fields.
E) circle the planet from pole to pole.
What is the light-gathering power of an 8 inch telescope compared to a 4 inch
telescope?
A) 2 times better
B) 4 times better
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C) 8 times better
D) 16 times better
E) 32 times better
According to the Zeeman effect, the splitting of a sunspot's spectral lines is due to
A) their rapid rotation.
B) temperature variations.
C) their magnetic fields.
D) their radial velocity.
E) a Doppler shift.
Which sequence of formation is most likely to be correct, oldest to youngest?
A) halo, spiral arms, globular clusters
B) globular clusters, open clusters, OB associations
C) planetary nebulae, Population I stars, population II stars
D) Population I stars, population II stars, population III stars
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E) emission nebulae, planetary nebulae, dark nebulae
When Saturn is at Equinox, its rings will
A) double the planet's brightness.
B) lie in the plane of the ecliptic.
C) contract closer to the planet's surface.
D) appear face-on to the earth.
E) lie perpendicular to the plane of the ecliptic.
Which of the following are the jovian planets?
A) Jupiter, Saturn, Uranus, Neptune, and Pluto
B) only Jupiter
C) only Jupiter and Saturn
D) Jupiter, Saturn, Uranus, and Neptune only
E) everything past Mars and the asteroid belt
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Which statement about the stages of starbirth is false?
A) At stage 1, only the cloud exists.
B) By stage 3, the star has formed a photosphere.
C) nuclear reactions begin in the core by stage 4.
D) The T-Tauri wind is prevalent in stage 5.
E) By stage 7, the star has reached the main sequence.
A meteorite is
A) a chunk of space debris that has struck the ground.
B) a streak of light in the atmosphere.
C) an icy body with a long tail extending from it.
D) a chunk of space debris orbiting the Earth.
E) an irregularly shaped body, mostly found orbiting between Mars and Jupiter.
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Noting the main sequence turnoff mass in a star cluster allows you to determine its
A) distance.
B) radial velocity.
C) age.
D) total mass.
E) number of stars.
One advantage of the Hubble Space telescope over ground based ones is that
A) it is larger than any Earth-based telescopes.
B) it can better focus X-ray images.
C) it can make better observations of the ozone layer.
D) its adaptive optics controls atmospheric blurring better.
E) in orbit, it can operate close to its diffraction limit at visible wavelengths.
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Because almost all galaxies show redshifted spectra, we know that
A) our understanding of redshift is wrong.
B) we must be at the center of the universe.
C) the universe is expanding.
D) the sky must be dark at night.
E) the universe is closed.
The Milky Way is considered to be an intermediately wound, barred spiral, which
would be type ________ according to Hubble.
A) E4
B) Sa
C) SBb
D) SBV
E) B2S
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Which of the following have an icy composition?
A) most asteroids
B) meteoroids
C) comets
D) the surface of Mars
E) meteorites and most asteroids
Why was Herschel's strategy for mapping our Galaxy flawed?
A) His infrared telescopes couldn't penetrate the dust clouds.
B) He used globular clusters, lying above the dust in the disc.
C) He relied on visual wavelengths, which are obscured by dust.
D) He used radio telescopes that didn't give enough resolution.
E) He assumed Earth was at the extreme edge of the Galaxy.
Which three played a role in the finding of Neptune?
A) Herschel, Hubble, and Einstein
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B) Newton, Einstein, and Tombaugh
C) Adams, Leverrier, and Galle
D) Bode, Herschel, and Fraunhofer
E) Shapley, Hubble, and Whipple
Which planet shows the widest range of surface temperatures between day and night?
A) Mercury
B) Venus
C) Earth
D) Mars
E) Uranus
The single most important determinant of the temperature, density, radius, luminosity,
and pace of evolution of a protostar is its
A) chemical composition.
B) magnetic field.
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C) spin.
D) mass.
E) molecular composition.
A major advantage of a Newtonian reflector over a refractor is
A) its compact size.
B) the elimination of chromatic aberration.
C) there are only two lenses to grind.
D) the central hole in the mirror is smaller.
E) the elimination of the secondary mirror.
In 1992, COBE observations revealed
A) that the universe had less than the critical density, so was open.
B) the microwave background radiation is not isotropic, but centered on Virgo.
C) the dark matter in the universe is normal (baryonic), so the universe is closed.
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D) there are small ripples in the microwave background, the seeds of galaxies.
E) the existence of dark energy.
During the hydrogen shell burning phase
A) the star grows more luminous.
B) the star becomes less luminous.
C) helium is burning in the core.
D) the core is expanding.
E) hydrogen is burning in the central core.
If the accepted value of H were to double,
A) the age of the universe would be twice as old as we originally believed.
B) the age of the universe would be half what we believed.
C) the Copernican principle would not be valid beyond our solar system.
D) the ages of the oldest globular clusters would be invalid.
E) the critical density would be halved.
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Explain the basic principle behind the VLA.
Most of the mass of the Milky Way seems to exist in the form of
A) population I stars in the disk.
B) population II stars in the Halo.
C) hydrogen gas in the disk and spiral arms.
D) dark matter out in the Halo.
E) the black hole in the Galactic Center.
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The best answer to both the flatness and horizon problems is
A) the Steady State Theory.
B) the GUT theory.
C) the inflationary epoch.
D) dark energy.
E) decoupling.
In what range of masses are most stars found?
A) 0.1 to 2 solar masses
B) 1 to 3 solar masses
C) 0.1 to 100 solar masses
D) 0.01 to 100 solar masses
E) Stars can have any mass.
For finding the distance to M31, Hubble relied upon
A) RR Lyrae stars in its globular clusters.
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B) Type I supernova in its core.
C) Type II supernova in its spiral arms.
D) Cepheid variables in its spiral arms.
E) planetary nebulae near its core.
Gravitational lensing of distant, faint irregular galaxies may be the key to
A) mapping dark matter.
B) quasar energy production.
C) understanding galactic rotation curves.
D) understanding active galactic nuclei.
E) determining galactic redshifts.
A star with a declination of +60.0 degrees will be
A) east of the vernal equinox.
B) west of the vernal equinox.
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C) north of the celestial equator.
D) south of the celestial equator.
E) None of these answers are correct.
The presence of a Mercurian magnetic field surprised the planetary scientists on the
Mariner 10 team because
A) Mercury is low in iron.
B) Mercury spins too rapidly to produce a stable dynamo.
C) it's still too hot for its core to have differentiated.
D) the dynamo theory predicted that Mercury was spinning too slowly for one.
E) Mercury lacks an iron core.
The largest presently known redshifts of quasars are close to
A) 0.96.
B) 3.
C) 7.
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D) 10.
E) 65.
Which property is common to spiral galaxies?
A) ongoing star formation and emission nebula in the arms
B) ongoing star formation and emission nebula in the halo
C) globular clusters in the nucleus
D) open clusters in the halo
E) very little internal structure
Why would observing in blue light give better resolution than red light when observing
objects close together in the same field of view?
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What were the two primary courses of heating that let the Earth differentiate?
The common element discovered in the Sun's spectrum before it was found here is
________.
What support for the solar nebula theory has come from observations of nearby young
stars?
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How does metal content vary between young disk stars and older halo stars? Why?
Our Moon and Mars both show very different hemispheres. Compare them and explain
why this occurred in each case.
How do the two factors (mass and distance) in Newton's law of gravitation each affect
the force on the two bodies?
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The ________ epoch explains the isotropy of the cosmic microwave background
mapped by COBE.
Give and explain an example of the use of the Doppler Effect on the highway.
Describe how the sun's rotation is responsible for observed polarities of sunspots.
Describe the relation between Mercury's spin and orbit.
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Which factor in the Drake equation is the most uncertain?
The ionized helium lines show up only in class ________ stars.
Why can we say a star spends its life trying to maintain equilibrium?
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The huge sheet of galaxies that spans 70 200 Mpc is called the ________.
When light escapes from near a black hole, we see a ________ red shift.
The dustiest and flattest spiral galaxies are in Hubble's class ________.

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