Extra Credit Problems (3 points maximum for each solution; organization and clarity matter)
- The star Polaris has a parallax of 0.00758 seconds of arc and an apparent magnitude of
 1.97, how far away is it, and what is its absolute magnitude?
- Formalhaut is an A3 V star in the constellation Piscus Austrinus with an apparent
 magnitude of 1.2. You may use the ClassAction Spectroscopic Parallax Simulator or use
 the H-R diagram below to find absolute magnitude. Use the method of spectroscopic
 parallax to determine how far away Formalhaut is. Show your own calculation of
 distance.
- The star Alnilam has a luminosity of about 240,000 times that of the Sun and a surface
 temperature of 25,000K. What is the radius of Alnilam?
- Albireo A is in a visual binary with a companion star Albireo B at an average distance of
 72 AU. The larger mass star (Albireo A) is 28 AU from the center of mass. If the period
 of the motion is 213 years find the mass of Albireo A and Albireo B.
Sample Solution