A Tour of VLA J2130+12

Narrator (April Hobart, CXC): As their reputation -- and very name - suggest, black holes are black. That is, once light passes a certain threshold of a black hole, called the event horizon, it never returns. This should make them virtually impossible to find. However, astronomers have found many black holes both here in our Milky Way galaxy and beyond. How is that possible? The answer is that regions immediately surrounding the black hole are often very bright in different types of light, including X-rays. That's because the black hole's immense gravitational pull can pull material away from a companion star at a high rate. This can create a swirling disk of heated material, generate enormous jets that reach across vast distances of space, or produce other telltale signs that we can observe with modern telescopes.

But what if a black hole is just sitting in space quietly, pulling in material at an unusually slow rate? It turns out that this might be more common than astronomers thought. A new result shows that a source within our Galaxy is actually a very quiet black hole - one that was never identified before as a black hole until now. It took data from many telescopes including Chandra, Hubble and several radio observatories to piece together all of the necessary information.

A team of researchers is now very confident that this source - known as VLA J2130+12 for short - contains a black hole a few times the mass of the Sun. This result suggests that the Milky Way galaxy could have thousands or even millions of these silent black holes. To find out if this is the case, astronomers will be looking to find them.