Dr. Paul Nandra, an astrophysicist at NASA has been studying a faraway galaxy named NGC 3516.
Scientists think that deep within the galaxy is a super-massive black hole.
Dr. Nandra studied the X-rays coming from the hot gases around the black hole. Artist's painting of the area around a black hole, though you can't actually see a black hole. You often see evidence of matter flying out of a black hole, but never falling in. First he had to find an X-ray telescope that could see NGC 3516. The satellite was built by Japan and the United States together, and is orbiting in space to observe interesting objects in the universe.