Black Holes – detection
Example: Like White Dwarf accretion disk but w/
black hole instead
Gas from red giant companion spills over towards black
hole
Gas spirals in toward black hole, through accretion disk
Gas will be much hotter because it falls further, to very small RS
Gas will be moving at very high velocity
Much faster than with white dwarf since much closer  (P2 a3)
Signature of black hole:  Very high energy release, very high
velocity
We find MASSIVE black holes in centers of most galaxies