The Sun is basically in balance at each point in its

 interior. What balance is that?

hydrostatic equilibrium, between net pressure 

force and self-gravity

The Sun's energy is produced at the present time

 mainly by

fusion of hydrogen into helium by the 

proton-proton chain

Nuclear fusion requires high temperatures because

 the nuclei that are fusing

are both positively charged and strongly repel 

each other 

Energy generated inside the Sun's core is 

transported to the surface by 

radiation on the inside and convection outside that

According to the "butterfly" diagram new sunspots 

at the beginning of a sunspot cycle tend to appear 

at fairly high latitudes, around 30-40 degrees N.

 or S.

Plages are found in which part of the Sun's 

atmosphere?

The solar neutrino problem turned out to be 

caused by a fundamental gap in our knowledge of 

Magnetic fields on the Sun are measured 

from absorption lines split into components by the 

Zeeman effect

Sunspots, flares, prominences, and coronal mass 

ejections are all caused by 

magnetic activity on the Sun

The curve connecting points in the H-R diagram for

 stellar models of the same initial mass but 

different ages is called a/an 

Which of the following evolutionary stages of a 

low-mass star is in the correct order of time?

main sequence, red giant branch, horizontal 

branch

Which evolutionary stage involves helium 

shell-burning?

asymptotic giant branch 

The "helium flash" is what happens

when the triple-alpha process ignites in 

electron-degenerate matter 

Electron degeneracy becomes important when 

a huge number of electrons are squeezed into a 

small volume 

Which of the following binary star systems 

exemplifies the so-called Algol "paradox"?

2 solar mass main sequence star, 0.7 solar mass 

subgiant 

The Chandrasekhar limit is 

the maximum mass of a star that can be 

supported by electron degeneracy pressure 

Stars on the upper end of the main sequence 

generate energy by which of the following 

processes?

CNO cycle, also called carbon cycle 

A Cepheid variable star with a period of 100 days 

is

a pulsating massive supergiant star 

In which of the following evolutionary stages is a 

high-mass star producing all of its energy by 

hydrogen shell-burning?

red supergiant

A really massive star in the late stages of its 

evolution will be generating energy in multiple 

shells each having a different fusion process, 

from silicon-burning in the innermost to 

hydrogen-burning in the outermost 

Nuclear exhaustion is what happens when 

a massive star has formed an iron core

The evolution of the most massive stars ends up 

with the star becoming a 

A pulsar is a 

rotating magnetic neutron star

An astronaut who falls into a black hole would be 

stretched because

the gravity changes dramatically over a short 

distance

The Sun is located in which region of the Milky 

Way?

The orbits of stars in the central bulge of the Milky 

Way are

highly eccentric and at random inclinations

The hot interstellar medium in the Milky Way is 

heated by which of the following?

Which of the following has the lowest 

temperature?

giant molecular cloud

If we want to see through the interstellar dust, for

 example in the direction of the galactic center, 

which region(s) of the electromagnetic spectrum 

should we use?

To which population does a globular cluster 

belong?

In general, the Milky Way 

has more heavy elements as time passes

We currently believe that the Milky Way formed 

from

several protogalactic clouds that came together

Where do the irregular galaxies belong in the 

Hubble "tuning fork" diagram?

on the opposite side of the spirals from the 

ellipticals 

The type of galaxy that has the highest percentage

 of gas and dust and most active star formation at

 present is the 

Where does most star formation occur in a spiral 

galaxy?

Which of the following can be used to estimate 

masses of elliptical galaxies?

the virial theorem, based on the width of an 

absorption line 

According to the unified model, a radio galaxy is 

an AGN that is viewed 

from the side, with the supermassive black hole 

and its accretion disk hidden by the torus

The cosmological principle says that 

the Universe looks the same on the large scale to

 all observers at a given cosmic time 

The redshifts of galaxies which appear in the 

Hubble Law are 

cosmological, from stretching of the wavelength by

 the expansion of the Universe

At the present time it appears that the expansion 

of the Universe is