Contrast finding the distances to seventh magnitude M3V and M3Ib ...

[armygirl]

Contrast finding the distances to seventh magnitude M3V and M3Ib stars.
 
  What will be an ideal response?

Question 2

Concerning dark energy, we do know
 
  A) combined with dark matter, it will ultimately produce a closed universe.
  B) its density remains constant over time, so it is not important in the early universe.
  C) that it is created when matter annihilates anti-matter.
  D) that it was revealed with Type II supernovae distances in the late 1990s.
  E) that it makes up 90 of all the matter and energy in the whole universe.

[nickk12214]

Answer to Question 1

An M3V main sequence star that bright would be close, and you could use regular parallax shifts over six months to fix its distance. But a huge supergiant that faint must be so distant that only spectroscopic parallax can give us a clue to its distance.

Answer to Question 2

B

[armygirl]

Thank you!

[nickk12214]

Always glad to help...