What do astronomers believe is located at the center of the Milky Way galaxy?

Understanding the nature and appearance of our galaxy is no small feat, for we live within a disk of obscuring gas and dust. Astronomers do not think that a supermassive black hole at the center of a galaxy is unique to the Milky Way. Rather, it appears to be quite typical of the almost innumerable galaxies in the observable universe. The fact that black holes may be the rule rather than the exception makes it even more important that we continue to study them.