Are names given to black holes? (Advanced)

Are names given to black holes? Does the Milky Way's black hole have a name? (Note: other astronomical bodies are named; why not black holes?)

To my knowledge, we don't name black holes themselves, but rather the sources that are thought to be associated with them. The reason is a purely practical one: by definition we can't see black holes, and astronomical names are generally assigned to objects that are found observationally (at any wavelength). In almost all cases, the presence of a black hole in or near any given source is established after the source is observed. So technically, the name belongs to the source that we see, not the black hole.

Take, for example, the black hole in the Milky Way. In the 1970s, a structure that was very bright in radio emission was discovered near the center of the galaxy - it was named Sagittarius A*. Many years later, we think that Sag A* likely surrounds the Milky Way's supermassive black hole; however, the name Sag A* still refers to the radio emission (whose origin is not completely understood) rather than to the black hole itself.

This page was last updated June 27, 2015.

About the Author

Kristine Spekkens

Kristine Spekkens

Kristine studies the dynamics of galaxies and what they can teach us about dark matter in the universe. She got her Ph.D from Cornell in August 2005, was a Jansky post-doctoral fellow at Rutgers University from 2005-2008, and is now a faculty member at the Royal Military College of Canada and at Queen's University.

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