Variable stars are ones whose ________ changes over time. Fill ...

[sarasara]

Variable stars are ones whose ________ changes over time.
 
  Fill in the blank(s) with correct word

Question 2

The satellite most critical to the study of the formation and structure of the universe is ________, which detected the ripples that led to galaxies.
 
  A) WMAP B) Fermi C) Planck D) HST E) COBE

[wtf444]

Answer to Question 1

luminosity

Answer to Question 2

C

[sarasara]

Gracias!

[bimper21]

Thanks for the timely response, appreciate it