MC1
A light-year is:
A. about 365 Earth days.
B. the time it takes a beam of light to circle the Sun.
C. the distance that light travels in a year.
D. the distance between the Sun and the nearest other star.
C. the distance that light travels in a year.
What are constellations?
A. ancient story boards, useless to modern astronomers
B. groups of stars making an apparent pattern in the celestial sphere
C. apparent groupings of stars and planets visible on a given evening
D. groups of galaxies gravitationally bound and close together in the sky
E. groups of stars gravitationally bound and appearing close together in the sky
B. groups of stars making an apparent pattern in the celestial sphere
How long does it take for a star like our Sun to form?
A. one billion years
B. 4.6 billion years
C. 100 thousand years
D. two million years
E. fifty million years
E. fifty million years
A year is defined as:
A. the time it takes for the Moon to complete a phase cycle.
B. the time it takes for the Sun to complete an orbit around Earth.
C. the time it takes for Earth to complete an orbit around the Sun.
D. the time it takes for the Moon to complete an orbit of Earth.
E. the time it takes for Earth to complete a rotation on its axis.
C. the time it takes for Earth to complete an orbit around the Sun.
How long is the precession cycle?
A. 29.5 days
B. 26,000 years
C. 1 day
D. 365.24 days
E. 18 years, 11.3 days
B. 26,000 years
Which event marks the birth of a star?
A. instability in an interstellar cloud
B. formation of a photosphere
C. fusion of hydrogen atoms into helium atoms
D. collapse of an interstellar cloud
E. formation of the planetary nebula
C. fusion of hydrogen atoms into helium atoms
The part of the Milky Way we are most familiar with is the:
A. Galactic center.
B. Corona.
C. Galactic disk.
D. Galactic halo.
E. Galactic bulge.
C. Galactic disk.
What is the absolute magnitude of our Sun?
A. -1.4
B. -23.0
C. +9.4
D. -4.6
E. +4.8
E. +4.8
The period-luminosity relation for Cepheid variables was discovered in 1908 by:
A. Harlow Shapley.
B. William Herschel.
C. Edwin Hubble.
D. Henrietta Leavitt.
E. Heber Curtiss.
D. Henrietta Leavitt.
Due to absorption of shorter wavelengths by interstellar dust clouds, distant stars appear:
A. to have a higher radial velocity.
B. brighter.
C. larger.
D. bluer.
E. redder.
E. redder.
The RR Lyrae stars all have periods of:
A. several hours.
B. several minutes.
C. several weeks.
D. less than a second.
E. several days.
A. several hours.
The total energy radiated by a blackbody depends on:
A. the fourth power of its temperature.
B. the square root of its temperature.
C. the cube of its temperature.
D. the square of its temperature.
E. the cube root of its temperature.
A. the fourth power of its temperature.
What would happen if mass is added to a 1.4 solar mass white dwarf?
A. The star's radius would increase.
B. The star would explode as a nova.
C. The core would collapse as a type II supernova.
D. The star would immediately collapse into a black hole.
E. The star would erupt as a carbon detonation (type I) supernova.
E. The star would erupt as a carbon detonation (type I) supernova.
Which is the correct description of the Sun's location within the Milky Way?
A. in the disk and about one-half a galactic radius from the center
B. in the disk but at its outer edge
C. as Herschel found, very close to the Galactic center
D. above the disk and about one-third of the galactic radius from the center
E. at the outer edge of the Galactic bulge but in the plane of the disk
A. in the disk and about one-half a galactic radius from the center
The radiation our eyes are most sensitive to lies in the color:
A. black at 227 nm.
B. violet at 7,000 Angstroms.
C. blue at 4,321 nanometers.
D. red at 6563 Angstroms.
E. yellow-green at about 550 nm.
E. yellow-green at about 550 nm.
Into how many constellations is the celestial sphere divided?
A. 88
B. 12
C. 110
D. 44
E. 57
A. 88
What celestial line is a product of the Earth's orbit around the Sun?
A. Equator
B. Ecliptic
C. Galactic Plane
D. Analemma
E. Prime Meridian
B. Ecliptic
An iron core cannot support a star because:
A. iron is in the form of a gas, not a solid, in the center of a star.
B. iron has poor nuclear binding energy.
C. iron is the heaviest element, and sinks upon differentiation.
D. iron supplies too much pressure.
E. iron cannot fuse with other nuclei to produce energy.
E. iron cannot fuse with other nuclei to produce energy.
While watching a star, you see it moves 15 degrees across the sky. How long have you been
watching it?
A. 3 hours
B. 1 minute
C. 15 minutes
D. 1 hour
E. 15 seconds
D. 1 hour
The Galactic Year is the time for our solar system to orbit the Galaxy; it is about:
A. 225 million years.
B. 13.5 billion years.
C. 9.6 billion years.
D. 15 million years.
E. 4.5 billion years.
A. 225 million years.
What is the force that keeps a main sequence star from blowing apart?
A. gravitation
B. radiation pressure
C. electron degeneration pressure
D. the strong force
E. magnetism
A. gravitation
What is one of the differences between Cepheids and RR Lyrae variables?
A. The period-luminosity relation holds only for RR Lyrae stars.
B. The pulsations of RR Lyrae stars are much less regular than those of Cepheids.
C. All Cepheids have the same brightness, but RR Lyrae stars vary greatly in
luminosity.
D. The RR Lyrae stars have much shorter periods than Cepheids.
E. Cepheids are giants, but RR Lyrae stars are still on the main sequence.
D. The RR Lyrae stars have much shorter periods than Cepheids.
Pulsars:
A. generally form from 25 solar mass stars.
B. spin very slowly when they're young, and gradually spin faster as they age.
C. emit radio waves in all directions.
D. are the cause of gamma-ray bursts.
E. spin very rapidly when they're young.
E. spin very rapidly when they're young.
An object more massive than the Sun, but roughly the size of a city, is a:
A. white dwarf.
B. neutron star.
C. brown dwarf.
D. red dwarf.
E. supernova remnant.
B. neutron star.
What is characteristic of a main sequence star?
A. It has a mass less than the Sun's.
B. Nuclear fusion in the core varies due to the amount of gravitational contraction
that occurs and which heavy elements are produced.
C. The rate of nuclear energy generated in the hydrogen to helium fusing core equals the rate radiated from the surface.
D. It has rapid rotation and a strong stellar wind.
E. All of the above are correct.
C. The rate of nuclear energy generated in the hydrogen to helium fusing core equals the rate radiated from the surface.
That Polaris will not always be the pole star is due to:
A. the Solar winds blowing the Earth farther away from the Sun.
B. precession shifting the celestial pole.
C. the Moon following the ecliptic, instead of the equator.
D. the sidereal day being shorter than the solar day.
E. the Earth's revolution being slightly less than exactly 365.25 days.
B. precession shifting the celestial pole.
It was the distribution of ________ that showed Harlow Shapley we were nowhere near the center of
the Milky Way in the 1920s.
A. emission nebulae
B. open clusters
C. planetary nebulae
D. globular clusters
E. supernova remnants
D. globular clusters
Seasons on Earth are primarily caused by:
A. the precession of the Earth's rotational axis.
B. the tilt of the Earth's rotational axis.
C. the distance from the Earth to the Sun.
D. the tilt of the Earth's magnetic axis.
E. the dates of the solstices and equinoxes.
B. the tilt of the Earth's rotational axis.
The place the Sun stops its northward motion along the ecliptic is the:
A. vernal equinox.
B. summer solstice.
C. prime meridian.
D. node of the ecliptic.
E. equator.
B. summer solstice.
By what mechanism does solar energy reach the Sun's photosphere from the layer just underneath it?
A. radiation
B. convection
C. ionization
D. conduction
E. differentiation
B. convection
Interstellar gas is composed of:
A. 10% hydrogen, 90% helium by numbers of atoms.
B. some hydrogen, but mainly carbon dioxide.
C. 90% hydrogen, 9% helium by weight.
D. ammonia, methane, and water vapor.
E. only hydrogen.
C. 90% hydrogen, 9% helium by weight.
17. The element with the most stable nucleus and smallest mass per particle is:
A. helium.
B. argon.
C. iron.
D. uranium.
E. hydrogen
C. iron.
27. The area in the Sun's atmosphere located above the chromosphere (1,500-10,000 km) where the
temperature rises dramatically is called the:
A. transition zone.
B. solar wind.
C. corona.
D. photosphere.
E. convection zone.
A. transition zone.
When the chromosphere can be seen during a solar eclipse, it appears:
A. yellow.
B. red.
C. invisible.
D. blue.
E. violet.
B. red.
For what type of object is the period-luminosity relation used for determining distances?
A. cataclysmic variables
B. Cepheids
C. RR Lyrae variables
D. planetary nebulae
E. T Tauri variables
B. Cepheids
What temperature is needed to fuse helium into carbon?
A. 15 million K
B. 100,000 K
C. 100 million K
D. 5,800 K
E. one billion K
C. 100 million K
Which statement is true about the interstellar medium?
A. Gas contains a lot of carbon atoms.
B. We know more about the gas than the dust.
C. Gas obscures the light from distant stars.
D. Dust is spread uniformly through the galaxy.
E. Dust blocks the longest electromagnetic wavelengths.
B. We know more about the gas than the dust.
____ 28. A star (no matter what its mass) spends most of its life:
A. as a protostar.
B. as a T Tauri variable star.
C. as a planetary nebula.
D. as a main sequence star.
E. as a red giant or supergiant.
D. as a main sequence star.
Which of these does NOT exist?
A. a 0.06 solar mass brown dwarf
B. a million solar mass black hole
C. a 6.8 solar mass neutron star
D. a 1.0 solar mass white dwarf
E. a 6 solar mass black hole
C. a 6.8 solar mass neutron star
From the Sun, the distance to the Galactic Center is about:
A. 100 billion pc.
B. 8 pc.
C. 100,000 pc.
D. 8,000 pc.
E. 225 million pc.
D. 8,000 pc.
Stars like our Sun emit most of their light in which part of the electromagnetic spectrum?
A. the ultraviolet
B. the visible
C. the radio
D. the X-ray
E. the infrared
B. the visible
What is it about the Sun's corona that astronomers don't understand?
A. The Sun's corona extends to the outer reaches of the solar system.
B. During total solar eclipses, the corona sometimes disappears from view.
C. No one knows why that part of the Sun's atmosphere does not drift away into
space.
D. The corona is much hotter than layers of the Sun that are closer to the solar
interior.
E. The corona seems to absorb 2/3 of the neutrinos that pass through it.
D. The corona is much hotter than layers of the Sun that are closer to the solar
A neon light (thin hot neon gas in a sealed tube) gives us:
A. nothing visible to us, but a lot of infrared lines as heat.
B. a lot of random bright red lines due to the motion of the hot atoms.
C. a few bright emission lines, telling us the gas is neon.
D. a continuous spectrum, since the neon is hot enough to glow.
E. a continuum, with dark lines identifying the neon atoms that are present.
C. a few bright emission lines, telling us the gas is neon.
An effective theory must:
A. must have been around for centuries or longer.
B. be continuously tested.
C. have been proven.
D. include mathematical formulae.
B. be continuously tested.
Which of the following elements contained in your body is NOT formed in the cores of stars during
thermonuclear fusion?
A. calcium
B. hydrogen
C. carbon
D. iron
E. aluminum
B. hydrogen
An emission spectrum can be used to identify a(n):
A. electron.
B. proton.
C. neutron.
D. atom.
E. neutrino.
D. atom.
Modern scientific theories are NOT:
A. testable.
B. perfect.
C. elegant.
D. simple.
E. continuously tested.
B. perfect.
The absolute magnitude of a star is its brightness as seen from a distance of:
A. one million kilometers.
B. ten parsecs.
C. one astronomical unit.
D. one light-year.
E. 10 light-years.
B. ten parsecs.
The overall dimming of starlight by interstellar matter is called:
A. absorption.
B. scattering.
C. reddening.
D. emission.
E. extinction.
E. extinction.
The stars appear to be attached to a sphere that surrounds the Earth and rotates above, causing the
apparent rising and setting of the stars. This is called the:
A. cosmos.
B. universe.
C. celestial sphere.
D. Sun.
E. constellations.
C. celestial sphere.