Homework #5
1. Mass of the Binary stars: 1.8 solar masses
2. Parsecs & Parallax: d = 1/p, so 1/12 of an arcsec
3. Most of the nearby stars are cool K and M stars.
4. m=-1.5, M=1.4. Recall 10 pc is about 30 lt. yrs.
Hard method: m M = -5 + 5log(d/1pc), so less than 30 years
5. d =145 pc, M = -5.2, so m = 0.6 (other answers bad)
6. Same M, one star is type G, one is type B. G is bigger.