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Review Questions for Astronomy 5 Midterm and Final
Midterm covers first 70 questions, Final covers all 105.
- A finger, held at arm’s length, fills an angle of about
A. 50 degrees. B. one hundredth of a degree. C. 2 degrees. D. one tenth of a degree. E. 10 degrees.
- The coordinate used in the terrestrial coordinate system to indicate angular distance north or south of the equator is A. azimuth. B. declination. C. longitude. D. altitude. E. latitude.
- The point in the sky that is located 90 degrees from the celestial horizon is the
A. node. B. equator. C. zenith. D. meridian. E. pole.
- Which of the following would be the coordinates of a star that is rising in the northeast?
A. azimuth 240 degrees, altitude 0 degrees B. azimuth 75 degrees, altitude 90 degrees C. azimuth 60 degrees, altitude 0 degrees D. azimuth 145 degrees, altitude 0 degrees E. azimuth 180 degrees, altitude 90 degrees
- How many seconds of arc are there in a degree?
A. 12 B. 60 C. 3600 D. 206265 E. 360
- The east-west coordinate in the terrestrial coordinate system is
A. latitude. B. altitude. C. longitude. D. right ascension. E. azimuth.
- What is the latitude of the North Pole of the Earth?
A. 0 degrees B. 90 degrees C. 180 degrees D. 270 degrees E. 45 degrees
- The north-south line that passes directly overhead is the
A. ecliptic. B. zenith. C. azimuth. D. horizon. E. meridian.
- Which of the following coordinates describes the angular distance of an object north or south of the celestial equator? A. latitude B. declination C. altitude D. right ascension E. azimuth
- Which of the following is true?
A. A sidereal day is equal to a solar day on Venus. B. A sidereal day is about 4 minutes shorter than a solar day on the Earth. C. A sidereal day is equal to a solar day on the Earth. D. A sidereal day is about 4 minutes longer than a solar day on the Earth. E. A sidereal day is the same for all planets.
- Suppose there is a star that rises at 10 p.m. tonight. At what time will it rise one month from now?
A. 9 p.m. B. midnight C. 8 p.m. D. 11 p.m. E. 7 p.m.
- An observer at a latitude of 41 degrees sees the Sun at the zenith at noon on which day(s)?
A. spring and fall equinox B. every 28 days C. never—impossible D. every day E. summer and winter solstice
- The ecliptic is the
A. apparent path of the Moon on the celestial sphere. B. plane of the Earth’s orbit projected onto the celestial sphere. C. projection of the Earth’s equator on the celestial sphere. D. plane of the Moon’s orbit. E. projection of the north celestial pole on the zodiac.
- The Sun moves eastward among the stars at the rate of about 30 degrees per
A. minute. B. month. C. hour. D. year. E. day.
- For what two planets is greatest elongation less than ninety degrees?
A. Venus and Jupiter B. Mercury and Mars C. Mercury and Venus D. Mars and Saturn E. Jupiter and Saturn
- What is the angular size of a 2 cm diameter coin at a distance of 1 km?
A. 4” B. 40’ C. 400’’ D. 40” E. 4’
- Why did Tycho Brahe reject Copernicus’s model of the solar system?
A. He could not detect stellar parallax. B. The ellipse had not been discovered yet. C. Tycho was convinced by Kepler that Copernicus was wrong. D. He could not detect retrograde motion for Mars. E. Tycho found mistakes in Copernicus’s calculations.
- The point of closest approach of a planet to the Sun is called the
A. perihelion. B. inferior conjunction. C. focus. D. epicycle. E. aphelion.
- Kepler’s law of equal areas in equal time predicts that
A. planets all must lie in the same orbital plane. B. comets are often in unbound orbits. C. the sun must be at the center of the solar system. D. planets move fastest at perihelion. E. planets are in noncircular orbits.
- Kepler’s Third Law states that
A. an object in motion remains in motion. B. the cube of the distance from the Sun is proportional to the square of the period around the Sun. C. a planet moves more rapidly when near the Sun. D. a planet’s mass increases with distance from the Sun. E. planets close to the Sun have longer periods than those further away.
- A hypothetical planet orbits the Sun a distance of 4 AU. What is its orbital period?
A. 64 years B. 16 years C. 8 years D. 2 years E. 4 years
- In the heliocentric model of the solar system, retrograde motion occurs when
A. one of the planets is nearest the Sun in its orbit. B. two planets are 90 degrees apart from each other. C. two planets are farthest apart. D. two planets pass each other in their orbits. E. two planets are on opposite sides of the Sun.
- Two planets have orbital periods of 3 years and 4 years, respectively. What is the synodic period of the two planets? A. 12 years B. 1.33 years C. 0.58 years D. 1 year E. 7 years
- Which of the following planets, when viewed from the Earth, can be seen at crescent phase?
A. Mars B. Neptune C. Saturn D. Mercury E. Jupiter
- Which of the following did Galileo use to support the heliocentric hypothesis?
A. existence of sunspots B. prograde motion of the planets C. phases of the Moon D. phases of Venus E. mountains on the moon
- Compared with your mass on Earth, your mass on the Moon would be
A. about 6 times more. B. you can’t fool me — exactly the same. C. about 36 times more. D. about 6 times less. E. about 36 times less.
- For an object to accelerate it must
A. remain motionless. B. change its speed. C. change its direction of motion. D. change its speed or direction of motion. E. change its speed and direction of motion.
- Assume that Saturn is 10 times as far from the Sun as the Earth is, and that it has 100 times the mass of the Earth. The gravitational force between Saturn and the Sun is A. 100 times the force between the Earth and Sun. B. 10 times the force between the Earth and Sun. C. equal to the force between the Earth and Sun. D. one-tenth the force between the Earth and Sun. E. 1/100 the force between the Earth and Sun.
- A telescope that uses a lens to bring radiation to a focus is called a
A. reflector. B. refractor. C. photometer. D. spectrometer. E. radio telescope.
- How does the light-gathering power of a 40 cm telescope compare to that of a 20 cm telescope?
A. 16 times as great B. 2 times as great C. 4 times as great D. 8 times as great E. they are the same
- Why do X-ray telescopes have to be placed in space satellites?
A. The mirrors for X-ray telescopes are too large to operate on ground. B. There is too much scattered sunlight in the Earth’s atmosphere. C. They are too dangerous for astronomers to operate on the ground. D. They are too sensitive to terrestrial radiation. E. The Earth’s atmosphere absorbs cosmic X-rays.
- A star with a trigonometric parallax of .02 arcseconds has a distance of
A. 2.0 light years. B. 50 pc. C. 20 pc. D. need more information (magnitudes) E. 4 kpc.
- By what factor would the brightness of a star increase if an observer moved from 5 parsecs to 1 parsec from the star? A. 125 times B. 25 times C. 15 times D. 625 times E. 5 times
- Two stars, which differ in magnitude by 5, have a brightness ratio of
A. 10:1. B. 5:1. C. 50:1. D. 1000: E. 100:1.
- How do the sun, a white dwarf, and a red giant rank in descending order of luminosity?
A. Sun, white dwarf, red giant B. red giant, Sun, white dwarf C. red giant, white dwarf, Sun D. Sun, red giant, white dwarf E. white dwarf, Sun, red giant
- Which of the following can produce a continuous spectrum?
A. a gas consisting entirely of molecules B. the Sun C. a hot gas at low density D. a cold gas at low density E. a hot solid
- Suppose the electron in an atom is in an excited orbit. What will happen to the electron if nothing disturbs the atom? A. It will move to the next excited orbit that has higher energy and then move back. B. It will move to the lowest energy orbit. C. It will fly away from the atom, ionizing the atom. D. It will move to another excited orbit that has higher energy. E. It will remain in the same excited orbit.
- The Sun is
A. a much smaller then average star, but with an average mass. B. an average star in mass and radius. C. a much larger than average star, but with an average mass. D. an average size star, but with much smaller than average mass. E. an average size star, but with much larger than average mass.
- The series of reactions that produce the Sun’s energy are called
A. helium flash. B. core reactions. C. chemical reactions. D. the proton-proton cycle. E. the solar cycle.
- The Sun will run out of fuel in about
A. 50 million years. B. 5 billion years. C. 5 thousand years. D. 5 million years. E. 50 billion years.
- Approximately how long does it take the energy produced in the Sun’s core to reach the Sun’s surface?
A. a year B. 5 billion years C. a second D. 1000 years E. 100,000 years
- What part of the Sun do astronomers learn about when they study neutrinos from the Sun?
A. sunspots B. the core C. the convection zone D. the photosphere E. the corona
- The age of a cluster can be estimated by
A. plotting the stars on a color-color diagram — lower values imply older. B. plotting the stars on an HR diagram — lower turnoff implies older. C. observing the number of stars — larger numbers imply older cluster. D. observing the number of stars — larger numbers imply younger cluster. E. plotting the stars on an HR diagram — lower turnoff implies younger.
- One reason that Cepheid stars are important to astronomers is that
A. they can be seen even in distant clusters of galaxies. B. they are especially rich in metal content. C. there is a definite relationship between variability period and luminosity. D. they are all in the plane of the galaxy — so center can be measured. E. they are very young, so stellar evolution can be studied in detail.
- All the stars in a cluster are usually assumed to have the same
A. temperature. B. luminosity. C. mass. D. main sequence lifetime. E. age.
- A protostar becomes a main sequence star when what happens?
A. when the star becomes a red giant B. the star begins to fuse hydrogen in the core C. when the star goes supernova D. the star becomes a blue supergiant E. the star begins to fuse helium in the core
- What information about a binary star system is needed in order to calculate the sum of the masses of the two stars? A. distance and spectral type B. orbital period and separation C. color and luminosity D. magnetic field and rotation period E. age and temperature
- Which of the following is not one of the stages of a pre-main sequence star?
A. Self-sustaining fusion B. Assembly of a protostar C. Radiative contraction D. Convective contraction E. Growth to a red giant
- What happened to the gas that was left over in the solar nebula after the planets formed?
A. It was blown away by a strong wind. B. It condensed to form the zodiacal light. C. It fell back into the Sun. D. It formed into another star which has since died. E. It was swept away by a passing star.
Note: Review first 70 for midterm, and all 105 for the final
- When a star is just evolving off the main sequence, which element is most common in the core?
A. hydrogen B. iron C. helium D. depends on spectral type E. carbon
- A white dwarf star such as Sirius-B balances the inward gravitational force by
A. energy from recurrent novae. B. degenerate neutron gas pressure. C. radiation pressure. D. gas pressure from heat derived from fusion. E. degenerate electron gas pressure.
- The object at the center of the Crab Nebula is
A. a neutron star. B. a massive O star. C. an X-ray binary. D. a white dwarf. E. a 10 solar mass black hole.
- Pulsars are
A. spinning neutron stars with beamed radio emission. B. white dwarfs with periodic stellar winds. C. binary systems with regular eclipses. D. pulsating red giant stars with close companions. E. black holes with accretion disks.
- The best observational evidence for the existence of black holes is
A. planetary nebulae. B. evolved red giants with masses in excess of 3 solar masses. C. supernova explosions. D. pulsar emission. E. massive, mass-transfer X-ray binaries.
- The approximate size of a white dwarf is
A. 1 AU. B. the size of the Earth. C. between 1.4 and 2.5 solar radii. D. the size of the Sun. E. 10 km.
- A light curve is a plot showing
A. mass versus luminosity. B. distance versus time. C. luminosity versus spectral type. D. brightness versus time. E. radial velocity versus magnitude.
- The Magellanic clouds are
A. nearby irregular galaxies gravitationally bound to the Milky Way. B. close clusters of galaxies about 10 Mpc away. C. regions of little gas and dust in the plane of the galaxy. D. regions of star formation in the Andromeda galaxy. E. an optical illusion caused by dust in the interplanetary medium.
- The expansion of the universe was discovered by
A. Hubble. B. Schmidt. C. Hertzsprung. D. Galileo. E. Penzias and Wilson.
- The masses of galaxies are often determined by
A. measuring their tidal forces on the Milky Way. B. determining their star formation rates. C. counting their stars. D. looking at their shape. E. measuring their rotation curves.
- Which of the following is true of Seyfert galaxies?
A. They are a form of elliptical galaxy. B. They have unusually bright nuclei. C. They have no spiral arms. D. They are all far smaller than quasars. E. They are all found in the Local Group of galaxies.
- How do we know that the quasars are at large distances?
A. They have large parallaxes. B. They are greatly obscured by interstellar dust. C. They are extremely dim. D. They appear fainter than most stars. E. They have large redshifts.
- Some quasars vary in brightness in only a few days. What does this tell us about the quasars?
A. They have large magnetic fields. B. They are quite small. C. They are made of neutrons. D. They must be highly luminous. E. They cannot emit radio waves.
- Quasars all have great distances. Why are there no nearby quasars?
A. No quasars have existed in the recent past. B. Nearby quasars emit light we cannot detect at the present time. C. Quasars are found only in clusters of galaxies. D. If quasars are too close to us, they look like pulsars. E. Quasars avoid spiral galaxies.
- Absorption lines in quasars usually have lower redshifts than the quasars themselves do. This suggests that the absorption lines are caused by A. gas in the quasar itself. B. gas between us and the quasars. C. gas directly behind the quasar. D. gas at the same distance as the quasars. E. gas that is farther away than the quasars.
- Which of the following statements about galaxies is true?
A. Galaxies are uniformly distributed throughout the universe. B. Galaxies are found both in small groups and large clusters. C. Most galaxies are well isolated from other galaxies. D. Most galaxies occur in isolated pairs. E. Spiral galaxies are smaller than most dwarf elliptical galaxies.
- The Local Group is
A. an example of a void. B. a supercluster that contains the Virgo Cluster. C. a group of about 30 to 50 galaxies containing the Milky Way galaxy. D. a large supercluster of galaxies centered on the Milky Way. E. the group of stars within 10 parsecs of the Sun.
- What type of galaxy is frequently found at the center of a rich cluster of galaxies?
A. dwarf elliptical B. Seyfert C. irregular D. giant elliptical E. spiral
- A rich cluster of galaxies contains about _____ galaxies.
A. 100,000, B. 100, C. 1000 D. 50 E. 1,000,
- Which of the following statements best describes the distribution of galaxies in the universe?
A. The galaxies are distributed uniformly in space. B. There are only a few dozen galaxies scattered about in our universe. C. There are many clusters near us in space, but nothing beyond. D. The galaxies lie on sheets surrounding empty regions. E. There are a few large clusters of galaxies with nothing in between.
- If we were to discover that Hubble’s constant is actually twice as large as it is now thought to be, how would that alter our estimate of the expansion age of the universe? A. Our estimate would be cut to one-quarter its present value. B. Our estimate would double. C. Our estimate would be cut in half. D. Our estimate would be unchanged. E. Our estimate would increase to 4 times its present value.
KEY Created: 6:37:07 PM PST
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