General Astronomy -
Spring 2013
Homework #3 - due February 11
1. (1 pt) Which is hotter, an G9V star or an F1I star? Which
is more luminous?
2. (3 pt) The spectral lines of two stars in a eclipsing binary
shift back and forth with a period of 2 months. The lines of
star A show shifts indicating an orbital speed of 10,000 m/s, the
lines of the star B indicated an orbital speed of 2,500 m/s.
What are the masses of stars A and B?
3. (3 pt) A star has an absolute bolometric magnitude of -0.3 and a
temperature of 4,300 K. What is its radius?
4. (3 pt) An A1V star has an apparent magnitude of mV = -3.4. How
far away is it?