© Image is courtesy of NASA’s Goddard Space Flight Center.
Screenshot of the NASA-produced animation showing a giant star being slowly devoured as it orbits the galaxy’s central black hole.
Pasadena, CA
— In a case of cosmic mistaken identity, an international team of astronomers revealed that what they once thought was a supernova is actually
periodic flaring from a galaxy where a supermassive black hole gives off bursts of energy every 114 days as it tears off chunks of an orbiting star.
Six years after its initial discovery — reported in
The Astronomer's Telegram by Carnegie's Thomas Holoien — the researchers, led by Anna Payne of University of Hawai'i at Mānoa, can now say that the phenomenon they observed, called ASASSN-14ko, is
a periodically recurring flare from the center of a galaxy more than 570 million light-years away in the southern constellation Pictor.
Their findings — based on 20 instances of regular outbursts — will be published in
The Astrophysical Journal and presented by Payne at the American Astronomical Society's annual meeting.
Active galaxies, such as the host of ASASSN-14ko, have unusually bright and variable centers. These objects produce much more energy than the combined contribution of all their stars. Astrophysicists think this is due to gravitational and frictional forces heating up a swirling disk of gas and dust that accumulates around the central supermassive black hole. The black hole slowly consumes the material, which creates low-level, random changes in the light emitted by the disk.
Comment: See also: