Astronomers have used NASA's Chandra X-ray Observatory to show that a supermassive black hole at the center of a group of galaxies has erupted multiple times over a period lasting about 50 million years. Evidence for the eruptions can be found in the cavities, or bubbles, carved out of the hot gas that envelops the galaxies and glows in X-rays. This composite image contains the X-rays from Chandra (pink) that have been combined with visible light data (gold).