The definition of astrophysics is a branch of astronomy that studies the composition and origin of objects in outer space along with the way they interact with each other and other matter.(noun)
A person who studies black holes, dark matter, and cosmic strings is an example of a person who is involved with astrophysics.
See astrophysics in Webster's New World College Dictionary
See astrophysics in American Heritage Dictionary 4
noun (used with a sing. verb)
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