Q&A: Black Holes
What is the meaning of the "*" in Sagittarius A*?
The name 'Sagittarius A*'
refers to the believed location of the supermassive black
hole in the center of our galaxy. About 50 years ago,
astronomers identified an area within the constellation of
Sagittarius that was the strongest region of radio emission
-- thus making it the likely center of the Milky Way.
Astronomers dubbed this region 'Sagittarius A' to identify
this particular area within the large patch of sky that this
constellation covers. As science and technology improved,
astronomers were later able to pinpoint a more exact location
of the suspected location of the supermassive black hole
through a variety of techniques. This improved location of
the black hole was then named Sagittarius A*
to separate it from the larger region of Sagittarius A.