If a sunspot has a temperature of 4,500 K and the surrounding solar surface has a temperature of ...

If a sunspot has a temperature of 4,500 K and the surrounding solar surface has a temperature of 5,800 K, how many times brighter is the surface compared to the sunspot?
 
  a. 0.28
  b. 0.36
  c. 2.8
  d. 3.6
  e. 36

Question 2

Theory predicts that neutron stars may not exceed 3 solar masses.
 
  Indicate whether the statement is true or false

Question 3

The corona of the sun can be observed
 
  a. during a lunar eclipse.
  b. with a coronagraph.
  c. using filtergrams.
  d. a and b above
  e. none of the above

Question 4

The event horizon marks the boundary within which the density is roughly the same as that of the atomic nucleus.
 
  Indicate whether the statement is true or false

Question 5

The ____ is (are) the hot gases that are the moving extension of the sun's corona.
 
  a. spicules
  b. prominences
  c. flares
  d. supergranules
  e. solar wind