Consider an X-ray binary system in which a compact object, ...

[chads108]

Consider an X-ray binary system in which a compact object, surrounded by an accretion disk, is in a binary orbit with another star. All of the following statements about such accretion disks are true except:
 
  A) The radiation from an accretion disk may vary rapidly in time.
  B) The compact object may be either a neutron star or a black hole.
  C) X-rays are emitted by the hot gas in the accretion disk.
  D) Several examples of flattened accretion disks being fed by a large companion star can be seen clearly in photos from the Hubble Space Telescope.
  E) The accretion disk consists of material that spills off the companion star.

Question 2

The nucleus of a comet is typically
 
  A) a few hundred kilometers across, and bright, shiny white from its ices.
  B) a few meters in diameter.
  C) located between the orbits of Mars and Jupiter.
  D) a few kilometers in size, and very low in density.
  E) very durable, made of iron.

[juwms]

Answer to Question 1

D

Answer to Question 2

D

[chads108]

Thank you!

[juwms]

Always glad to help...