Which effects have been useful (and successful) in the search for and identification of black holes in the universe?
A) influence of their intense gravitational field on atoms that are emitting light from the event horizons of the black holes
B) their gravitational influence on nearby matter, particularly companion stars
C) effect of their angular momentum, or spin, on nearby matter
D) their magnetic fields and the influence of these fields on nearby matter

Question

Quizplus · Accepted Answer

The gravitational influence of black holes on nearby matter, especially companion stars, has been a key method in identifying black holes, as it allows astronomers to infer the presence of a black hole by observing the motion of nearby objects.

Which Effects Have Been Useful (And Successful) in the Search