

An artist's illustration shows a supermassive black hole, with a center millions to billions times the mass of our sun, surrounded by matter flowing onto what is termed an accretion disk. Supermassive black holes are enormously dense objects buried at the hearts of galaxies. This disk forms as dust and gas in the galaxy falls onto the hole, attracted by its gravity. Also shown in the illustration, which NASA released Feb. 27, 2013, is an outflowing jet of energetic particles, believed to be powered by the black hole's spin. JPL-Caltech/NASA/Reuters
A supermassive black hole at the center of a remote galaxy digests the remnants of a star, in this artist's rendering. NASA's Galaxy Evolution Explorer had a 'ringside' seat for this feeding frenzy, using its ultraviolet eyes to study the process from beginning to end. The artist's work chronicles the star being ripped apart and swallowed by the cosmic beast over time. First, the intact sun-like star (left) ventures too close to the black hole, whose gravity overwhelms its own self-gravity. The star then stretches apart (middle yellow blob) and eventually breaks into stellar crumbs, some of which swirl into the black hole (cloudy ring at right).
This illustration depicts a supermassive black hole at the center of a galaxy. NASA's Galaxy Evolution Explorer found evidence that black holes – once they grow to a certain size – stifle the formation of new stars in elliptical galaxies. Black holes are thought to do this by heating up and blasting away the gas that fuels star formation. The blue color here represents radiation pouring out from material very close to the black hole. The grayish structure surrounding the black hole, called a torus, is made up of gas and dust.
This artist's concept illustrates a black hole that NASA unexpectedly discovered in 2002, about 32,600 light-years away.
A supernova within the galaxy M100, which may contain the youngest known black hole in our cosmic neighborhood, is seen in this composite image. Chandra's X-rays are colored gold, optical data from ESO's Very Large Telescope are yellow-white and blue, and infrared data from Spitzer are red. X-ray observations suggest that the supernova, a mere 50 million light-years away in a neighboring galaxy, is a black hole in the making, a team of US and European astronomers says. Chandra X-ray Observatory Center/Reuters
An artist's conception shows M33 X-7, a binary system in the galaxy M33 where a black hole is in orbit with a large star. Material from the large blue companion star is seen being pulled toward the black hole by its powerful gravity. A disk of this material (orange) is swept into orbit around the black hole, fed by winds flowing out from the star. This wind is disrupted by the black hole, causing turbulence and ripples beyond the disk.
This artist's rendering shows the most powerful pair of jets ever seen from a stellar black hole. This microquasar blows a huge bubble of hot gas 1,000 light-years across – twice as large and tens of times more powerful than other known microquasars. Scientists at the European Southern Observatory spied a pair of gigantic bubbles of hot gas coming from a stellar black hole, about 12 million light-years from Earth, as pictured in this artist's rendering from the observatory. The bubbles are the most powerful microquasars seen by astronomers, according to a study published in the journal Nature. European Southern Observatory/L.Calcada/AP
This illustration depicts how the catastrophic destruction of a star that came too close to a supermassive black hole may have occurred. A close encounter with another star put the doomed star (orange circle) on a path that took it near a supermassive black hole. The enormous gravity of the giant black hole stretched the star until it was torn apart. Because of the momentum and energy of the accretion process, only a few percent of the disrupted star's mass (indicated by the white stream) was swallowed by the black hole, while the rest was flung away into the surrounding galaxy.
This composite image of the radio galaxy 3C321 shows the jet from a black hole at the center of the larger galaxy (lower left) striking the edge of a companion galaxy (upper right), the first time such an interaction has been found. The image includes X-ray data from Chandra (colored purple), optical and ultraviolet (UV) data from Hubble (red and orange), and radio emission from the Very Large Array (VLA) and MERLIN (blue).
A growing black hole, called a quasar, can be seen at the center of a faraway galaxy, in this artist's concept. Astronomers using NASA's Spitzer and Chandra space telescopes discovered swarms of similar quasars hiding in dusty galaxies in the distant universe. The quasar is the orange object at the center of the large, irregular-shaped galaxy. It consists of a dusty, doughnut-shaped cloud of gas and dust that feeds a central supermassive black hole. As the black hole feeds, the gas and dust heat up and spray out X-rays, as illustrated by the white rays.