Statistical evidence
a. can be used to draw conclusions about a specific cases.
b. is applicable to classes of objects where only a few objects from the class have been studied.
c. allows scientists to determine the mechanism that produces the dust ring in Centaurus A.
d. allows scientists to deduce general characteristics about a class of objects with similar properties.
e. provides insight into the behavior of an individual object based on careful observations of it.
Question 2Which of the following nuclear fuels does a one-solar-mass star fuse over the course of its entire evolution?
a. hydrogen
b. hydrogen and helium
c. hydrogen, helium and carbon
d. hydrogen, helium, carbon, and neon
e. hydrogen, helium, carbon, neon, and oxygen
Question 3Galaxies may contain a supermassive black hole at their center but ___________ an active nucleus because of ____________ into the black hole
a. show; mass inflow
b. not show; mass inflow
c. show; lack of mass inflow
Question 4The triple-alpha process
a. controls the pulsations in Cepheid variable stars.
b. is the nuclear fusion of hydrogen to helium in massive stars.
c. is the process that produces the neutrinos we receive from the Sun.
d. requires a temperature of about 5,000,000 K to operate.
e. occurs during helium flash.
Question 5____________ galaxies contain a supermassive black hole at their centers while active nuclei are present in ____________of galaxies
a. Most; a few percent
b. Most; the majority
c. A small minority; a few percent
d. A small minority; the majority
Question 6Star clusters are important to our study of stars because
a. all stars formed in star clusters.
b. the Sun was once a member of a globular cluster.
c. they give us a method to test the our theories and models of stellar evolution.
d. they are the only objects that contain Cepheid variables.
e. All of the other choices are correct.
Question 7Soon after discovery, it was observed that quasars had a starlike appearance which was blurred by Earth's atmospheric seeing. Despite the blurring, it was realized that the intense energy-emitting regions of quasars must be small because they
a. have high radial velocities.
b. are very luminous.
c. are surrounded by quasar fuzz.
d. radiate huge amounts of energy.
e. fluctuate rapidly on time scales as short as a few hours.