Sagittarius A* is a bright object at the center of the Milky Way Galaxy. It is a radio source, giving off strong radio waves. It is near the border of the constellations Sagittarius and Scorpius. It is part of a larger astronomical feature called Sagittarius A. Astronomers think it is the site of a supermassive (very large) black hole. 
References[change | change source]
- Reynolds C. 2008. Astrophysics: bringing black holes into focus. Nature 455 (7209): 39–40. Bibcode:2008Natur.455...39R. doi:10.1038/455039a. PMID 18769426.