Choose only one answer for each question.
1. We observe a binary system consisting of two stars, Stars A and B.
Star A is a Main Sequence star with 3 solar masses, and Star B has evolved
slightly off the Main Sequence and has 1.5 solar masses. What can we
conclude?
a. Star A started to evolve off the Main Sequence, but then Star B
swept up its red giant envelope and made it go back to the Main Sequence
b. Star B is a Cepheid that is currently in its low-mass phase
c. Star B was originally more massive than Star A, then when it became a
red giant, some of its mass transferred to Star A
d. Stars A and B were originally one star, which split when it became a
red giant.
2. What is the difference between a type I and a type II supernova?
a. a type I supernova happens to a more massive star than a type II
b. a type I supernova happens to a massive star, a type II to a white dwarf
c. a type I supernova happens to a white dwarf, a type II to a massive star
d. the remnant of a type I supernova is a pulsar, and the remnant of
a type II supernova is a white dwarf
3. A type I supernova can be up to ____________ times as luminous as
the sun (i.e. as luminous as ___________ suns)
a. a few thousand (104)
b. a million (106)
c. a billion (109)
d. a trillion (1012)
4. What is required for a white dwarf supernova to occur?
a. the white dwarf must have a binary companion with more than 10 solar
masses
b. the white dwarf must have a Main Sequence binary companion
c. the white dwarf must be gaining mass from its binary companion
d. the white dwarf must lose all of its remnant heat
5. What powers a massive-star supernova?
a. gravitational potential energy from core collapse
b. fusion of iron into gold
c. neutrino emission
d. nuclear fission of massive elements