Author Question: Most of the halo stars are very old. Indicate whether the statement is true or ... (Read 10 times)

Mr. Wonderful · **on:** Jul 27, 2018

Most of the halo stars are very old.

Indicate whether the statement is true or false

Question 2

The key to identifying a black hole candidate in a binary system is that

A) one of the two stars cannot be seen.
B) the unseen companion in the system must have a sufficiently high mass.
C) the unseen star is a contact binary.
D) the system must be a very strong source of radio emissions.
E) the visible companion must be an evolving main sequence or giant star.