Question

1. What is the chemical composition of the core of a one solar mass star during the red super giant (asymptotic giant) phase? a) mainly carbon and oxygen b) mainly helium c) mainly hydrogen 2. What kind of stellar remnant will be left when the sun dies? a) red giant b) black hole c) white dwarf d) neutron star Which of the following Is not true of the cosmic background radiation? a) it is nearly equally bright in all directions b) it is starlight c) It was produced about a million years after the beginning of the expansion d) It is brightest in the radio (microwave) part of the spectrum 2. Which spatial geometry implies a finite universe a) closed b) flat c) open 3. A photon leaving a region of extremely strong gravity a) will be unaffected b) will lose energy and thus slow down c) will lose energy and thus be redshifted d) will gain energy and thus be blueshifted 4. As a degenerate gas is heated it will a) expand substantially b) contract substantially c) neither expand nor contract substantially d) alternate between expansion and contraction 5.How far away from sun, in light years in the closest star? a) 4.3 light years b) 1.4 light years c) 0.3 light years d) 6.2 light years

Answer 1

1)The chemical composition of the core of a one solar mass star during the red super giant phase is a) mainly carbon and oxygen.

During the E-AGB phase, the main source of energy is helium fusion in a shell around a core consisting mostly of carbon and oxygen.

2)As such, when our Sun runs out of hydrogen fuel, it will expand to become a red giant, puff off its outer layers, and then settle down as a compact white dwarf star, then slowly cooling down for trillions of years.

Hence the correct answer is c)white dwarf.

3)CMB radiation is not star light.

Hence correct option is b)

4)Closed spatial geometry implies a finite universe.It should have a positive curvature.

Hence the correct option is a) closed.

5)A photon leaving a region of extremely strong gravity will c) lose energy and thus be red shifted.

This is called gravitational red shift.

6)As a degenerate gas is heated it will C) neither expand nor contract substantially.

This is the case for white dwarfs and the cores of low-mass stars.

7)Closest star from sun is Proxima Centauri which is 4.244 light years away from sun.

Hence the correct answer is a) 4.3 light years