Which of the following is true of O and B stars? A) Their ...

[asan beg]

Which of the following is true of O and B stars?
 
  A) Their parallax is too small to measure.
  B) They are not found in associations.
  C) They reveal parts of six spiral arms near the Sun.
  D) Their distances cannot be measured by spectroscopic parallax.

Question 2

The mass of the Milky Way Galaxy can be estimated by:
 
  A) the orbital motions of the stars within the galaxy.
  B) the mass of the planets in the Solar System.
  C) the luminosity of the stars of the neighboring galaxies.
  D) the concept laid down by the spiral density wave theory.

[yasmin]

Answer to Question 1

A

Answer to Question 2

A

[asan beg]

Both answers were spot on, thank you once again

[yasmin]

Great! Please up vote