ASTR 1020


1. Estimate the radius of the Earth if it were collapsed to the density of a Neutron Star.

2. An 8km radius neutron star is spinning 1000 times per second. Calculate the speed of a point on its equator. Compare to the speed of light.

3. Given that the Schwarzschild radius for the Sun is 3km, and radius is proportional to mass, calculate the Schwarzschild radius of a 100kg human and a 1011 solar mass galaxy.

4. Using Newtons Laws, and the formula for the Schwarzschild radius, calculate the acceleration due to gravity at the surface of a one solar mass black hole. Redo for a 1012 solar mass black hole.

5. Explain why an HII region appears red in the visible part of the spectrum.

6. Draw a side-on view of the Milky Way. Identify where one would go to search for heavy metals. Explain your reasoning.

7. What are the Magellanic Clouds? How do they differ from the Milky Way? Do they have any effect on the Milky Way?