What is main-sequence fitting? A) a way of forcing stars to ...

[joe]

What is main-sequence fitting?
 
  A) a way of forcing stars to fit into a standard main sequence, even when they have some unusual characteristics
  B) a method for determining the age of a star cluster
  C) a method for determining the distance to a star cluster by assuming that its main sequence should line up with the main sequence on a standard H-R diagram
  D) the way we construct an H-R diagram by plotting the surface temperatures and luminosities of stars

Question 2

The distance to a star with a parallax angle of 0.2 arc seconds is
 
  A) 0.2 parsec. B) 2 parsecs. C) 5 parsecs. D) 12 parsecs. E) 20 parsecs.

[Beatricemm]

Answer to Question 1

C

Answer to Question 2

C

[joe]

Thanks for the timely response, appreciate it

[Liddy]

Wow, this really help