In the dense heart of the Milky Way, not only does a supermassive black hole reign, but a cloud of stellar-mass black holes ...

Sgr A*, in turn, is dwarfed by some supermassive black holes detected in other large galaxies such as one with a mass 6.5 billion times greater than that of the sun in a galaxy called Messier 87. That ...

Discovered by Charles Messier in 1764, M20 is a star-forming nebula located 9,000 light-years away from Earth in the constellation Sagittarius. The Orion Nebula (also known as Messier 42 or NGC 1976) ...