If our universe is expanding, what are the implications for the separation between two stars within our galaxy?   A. The two stars are moving farther apart.   B. The two stars are moving closer together.   C. The distance between the two stars is unaffected.    D. The question is impossible to answer without more information.

Some intergalactic properties. Use excel calculator to fill in the missing calculations. 1pc = 3.26 ly

The theory that waves of compression move around the galaxy triggering star formation is called   a. the flocculent theory.   b. the spiral compression theory.   c. the density wave theory.   d. the differential rotation theory.   e. none of the above.

Which of the following objects would you expect to be lacking any stars older than 10 billion years? a. an open cluster about 400 light years from the sun O b. a globular cluster O c. The Andromeda Galaxy (the nearest spiral galaxy to the Milky way) O d. M87 (a very massive elliptical galaxy)

The ________________ in other galaxies should contain luminous O and B stars if they are like the Milky Way.   a. halos   b. bulges   c. spiral arms   d. globular clusters   e. coronas

In an open universe, the overall geometry of the Universe would be a. flat b. spherical c. hyperbolic

2. A galaxy cluster has a galaxy behind it whose image we see as being smeared out and curved, with an angular radius of curvature on the sky of θE.  The background galaxy is at redshift zgal and the cluster is at zclust.  What is the mass of the cluster in solar masses?  Give your response in scientific notation with one decimal place.  (The Hubble constant is of course 70 km/s/Mpc, and you can assume the Hubble law for these low redshifts).   Values: zgal = 0.11 zclust = 0.07 θE = 117.4 arcseconds

The galactic corona is believed to contain mostly   a. O and B stars.   b. G, K, and M stars.   c. open clusters.   d. globular clusters.   e. dark matter.

List the following 5 terms in order through a stars life cycle (starting with the sun), through the remainder of its lifetime: a. Black dwarf b. Planetary nebula c. Red giant d. Star (Sun) e. White dwarf

2. What features vary from one galaxy to the next?