0.721569	0.312784	0.1333	The light we see from the Sun’s disk comes from which layer ? a. troposphere b. chromosphere c. photosphere d. ionosphere e. corona	c
0.865258	0.96183	0.249535	The temperature of the layer of gas that produces the visible light of the Sun is: a. 3,500 K b. 5,800 K c. 12,300 K d. 300,000 K e. 15 million K	b
0.624349	0.915175	0.794069	What is the net result of the proton-proton chain ? a. 2 protons make deuterium + 1 neutrino b. 2 heliums are fused into 1 carbon, 1 neutrino + energy c. 4 hydrogens are fused into 1 helium, 2 neutrinos + energy d. 2 hydrogens and 1 helium are fused into 1 carbon + energy e. 3 helium 4 fuse to make C 12	c
0.862574	0.885645	0.789765	What is the meaning of the “solar constant” ? a. The Sun’s position in the Milky Way is central and immobile b. The regularity of the sunspot cycle has not changed since Galileo c. The size of the Sun never changes d. The solar energy reaching Earth per unit area per unit time e. Like Venus, the surface appearance of the Sun is featureless	d
0.982123	0.726337	0.013205	By what mechanism does solar energy reach the Sun’s photosphere from the layer just underneath it? a. differentiation b. ionization c. radiation d. convection e. conduction	d
0.242189	0.459538	0.008131	The pattern of rising hot cells all over the photosphere is called: a. filaments b. granulation c. sunspots d. convective projections e. prominences	b
0.621262	0.824288	0.908388	When the chromosphere can be seen during a solar eclipse, it appears: a. invisible b. violet c. blue d. yellow e. red	e
0.173094	0.66393	0.732609	The numbers of sunspots and their activity peak about every: a. 36 days b. six months c. year d. eleven years e. 76 years	d
0.131956	0.785611	0.794297	A nearby star has a parallax of 0.2 arc seconds. What is its distance ? a. 0.1 parsec b. 0.2 parsec c. 0.5 parsec d. 5 parsecs e. 50 parsecs	d
0.188608	0.832312	0.299405	What is proper motion ? a. It is the true, not apparent, motion of a star in space b. It is the apparent shift as we go to opposite sides of our orbit every six months c. It is the annual apparent motion of a star across the sky d. It is the motion of a star towards or away from us, revealed by Doppler shifts e. It is the orbital motion of a star around the Galaxy	c
0.542368	0.121799	0.661094	The absolute magnitude of a star is its brightness as seen from a distance of: a. one millions kilometers b. one astronomical unit c. one light-year d. ten parsecs e. 10 light years	d
0.878823	0.070771	0.023372	What physical property of a star does the spectral type measure ? a. density b. luminosity c. temperature d. mass e. composition	c
0.040583	0.37325	0.244968	The most famous G type star is: a. Polaris b. Betelgeuse c. Sirius d. The Sun e. Pollux	d
0.062161	0.064194	0.542762	Stars that have masses similar to the Sun’s and sizes similar to the Earth are: a. main sequence stars b. white dwarfs c. red giants d. red dwarfs e. brown dwarfs	b
0.544757	0.24936	0.738033	The Hertzsprung-Russell Diagram plots _________ against the spectral type or temperature. a. distance b. luminosity or absolute magnitude c. brightness or apparent magnitude d. size or density e. mass	b
0.346225	0.427079	0.429025	What characteristic of the stars in a binary system can be determined by knowing the period of the star’s common orbit and the distance between them? a. their apparent brightness b. their absolute magnitudes c. their densities d. their masses e. their temperatures	d
0.055402	0.706942	0.114154	What effect does dust have on visible light passing through it ? a. It dims and reddens it b. It completely blocks all visible light from passing through c. All light is turned bluish in color d. It makes the light coming from stars appear to twinkle e. It ionizes the light and creates emission lines	a
0.603421	0.777174	0.698021	Some regions of the Milky Way’s disk appear dark because: a. there are no stars there b. stars in that direction are obscured by interstellar gas c. stars in that direction are obscured by interstellar dust d. the magnetic field has directed the polarized light away from these regions e. there are numerous black holes there that capture all the star light behind them	c
0.48855	0.869735	0.416708	The most common molecule in a molecular cloud is: a. methane, CH4 b. molecular hydrogen, H2 c. carbon monoxide, CO d. water, H2O e. ammonia, NH3	b
0.72652	0.362779	0.448306	What makes the subject of star formation so difficult and complex ? a. It is so slow that no visible proof of it exists b. Star formation is too expensive to study in detail c. Stars live too long to be observed from birth to death d. Clouds, fragments, protostars, stars, and nebulae all interact and influence each other e. Shock waves disrupt the orderly evolution of stars	c
0.338485	0.075113	0.673466	What is characteristic of a main sequence star ? a. It has a mass less than the Sun’s b. It has rapid rotation and a strong stellar wind c. Nuclear fusion in the core varies due to the amount of gravitational contraction that occurs and which heavy elements are produced d. The rate of nuclear energy generated in the hydrogen to helium fusing core equals the rate radiated from the surface e. All of the above are correct	d
0.952531	0.498847	0.624093	Why are star cluster almost ideal “laboratories” for stellar studies ? a. All stars in the cluster are the same size and luminosity b. Their combined light makes them much easier to spot from a distance c. Stars in clusters have the same age, similar composition, and are at the same distance away d. Stars in clusters are all relatively young and therefore shine brightly e. Like our Sun, stars in cluster are always located in the plane of the Milky Way Galaxy	c
0.129937	0.514216	0.04609	A star spends most of it life: a. as a protostar b. as a main sequence star c. as a planetary nebula d. as a red giant or supergiant e. as a T Tauri variable star	b
0.451308	0.468672	0.850955	The order of evolutionary stages of a star like the Sun would be Main Sequence, giant, planetary nebula, and finally: a. hypernova b. neutron star c. white dwarf d. nova e. black hole	c
0.976041	0.238359	0.080261	What are black dwarfs ? a. the lowest mass main sequence stars b. the end result of massive star evolution c. objects that are not quite massive enough to be stars d. pulsars that have slowed down and stopped spinning e. cooled off white dwarfs that no longer glow visibly	e
0.645385	0.694592	0.566138	A ________________ is a relatively gentle mass-loss event which allows a star to peacefully readjust its structure into a white dwarf configuration. a. dark nebula b. emission nebula c. planetary nebula d. nova e. supernova	c
0.599465	0.703585	0.402638	A high-mass star dies more violently than a low-mass star because: a. it must always end up as a black hole b. it has a much higher luminosity and eventually it core collapses very suddenly c. it cannot fuse elements heavier than carbon d. gravity is weakened by its high luminosity e. it is most often found as part of a binary system	b
0.5152	0.836806	0.602868	What characteristic of a star cluster is used to determine its age ? a. the ratio of main sequence to white dwarf stars b. the number of red giants c. the faintest stars seen in the cluster d. the main sequence turnoff e. the total number of stars in the cluster	d
0.828656	0.948364	0.067771	An iron core cannot support a star because: a. iron is the heaviest element, and sinks upon differentiation b. iron has poor nuclear binding energy c. iron cannot fuse with other nuclei to produce energy d. iron supplies too much pressure e. iron is in the form of a gas, not a solid, in the center of a star	c
0.485462	0.806754	0.305367	A star can be a supernova: a. in predictable cycles of decades b. a few times, at unpredictable intervals c. only if it can fuse iron in its core d. before it reaches the main sequence, if it is massive enough e. only once	e
0.576502	0.194995	0.489631	What produces a type-I supernova ? a. the collapse of the core of a massive star b. the helium flash blows apart a giant’s core c. mass transfer onto a white dwarf pushing it over 1.4 solar masses d. a nova igniting a helium flash in its red giant companion e. the radioactive decay of nickel 56 into cobalt 56 into iron 56	c
0.180643	0.509174	0.790056	What evidence is there that supernovae really have occurred ? a. the Crab Nebula b. supernova remnants c. existence of heavy radioactive elements in nature d. observations of the actual explosions e. all of the above	e
0.846864	0.138214	0.852547	Type II supernovae occur: a. after Type I supernovae b. when two pulsars collide c. because of the Hubble limit d. when low-mass stars reach the end of their lives e. when the core of a high-mass star collapses	e
0.60583	0.894025	0.311881	Of the common elements in your body, the only one not formed in stellar nucleosynthesis is: a. iron b. calcium c. hydrogen d. carbon e. oxygen	c
0.382243	0.358395	0.256711	In the Lighthouse model: a. pulsars are observable only if they lie in the galactic plane b. pulsars are navigational devices created by interstellar navigators as discovered by Jocelyn Bell in 1967