But there usually is a scientific story that can be told just by looking over the image. The Hickson group, in the constellation of Capricorn, is at a distance from Earth of 400 million light years. For comparison, our galaxy, the Milky Way, extends about 100,000 light years across. To its right is an elliptical galaxy, 87b, that appears as a bright round blotch. Elliptical galaxies are thought to be the result of a collision between two spiral galaxies.
Gas is thrown out, the arms fall off and what's left is an elliptical galaxy.
The galaxies are leaving each other alone for the mean time, so it is thought that past interactions between them produced gas to light up the galaxies, Charlton said. In the meantime, the pair of galaxies is being tormented by nearby gas-sucking black holes, Charlton said. Black holes cannot be seen but are theorized to be nearby because the image shows the nuclei of the galaxies are very active and spewing gas. A third group member, the nearby spiral galaxy 87c at the top of the image, may be undergoing a burst of active star formation, Charlton said. But it also is likely to merge in coming years with the larger galaxy beneath it in the image.