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Homework #4
•Q4.
d =145 pc, M = -5.2, use m – M = -5 + 5log(d/1pc), so m = 0.6 (other answers bad)
•Q5.
Sirius: m=-1.5, M=1.4. Recall 10
pc is about 30 lt. yrs, and M = m at 10 pc. m < M, so Sirius must be
closer than 10 pc!
–Hard
method: m – M = -5 + 5log(d/1pc), so less than 30 years
•Q6:
Binary system SS Cygni: use
