We have long suspected that at the heart of our Milky Way galaxy is a massive black hole. It’s tough to check this out directly, since flying there in a fast jet would take seventeen thousand million years. Besides, we’d never make it back, because black holes suck in mass and emit no light. That’s why they are impossible to see.
However, advances in optics have enabled scientists to peer into the heart of the Milky Way with new clarity. Now they are able to observe faint stars that used to be almost invisible. The motion of one such star, called S2, gives us very strong evidence that our galaxy, the Milky Way, does indeed have a hole in it’s heart – a black one at that!
S2 rapidly orbits the outskirts of the leading candidate for black hole status. Under the powerful gravitational pull of the black hole, S2 gets as close as seventeen light hours to it. The data on it’s elliptical orbit, which it completes in a mere 15 years, lightning speed on the grand scale of the universe, indicates that the Milky Way’s black hole has a mass of 3.7 million times that of our sun, which takes an estimated two hundred and thirty million years to make it’s big trip round the Milky Way.
So next time you try to find something around the house, think about those scientists who are trying to find an invisible black hole, lurking somewhere inside our galaxy.