SN 2006gy was an extremely energetic supernova, sometimes referred to as a hypernova or quark-nova, that was discovered on September 18, 2006.
What is SN 2006gy?
SN 2006gy was first observed by Robert Quimby and P. Mondol, and then studied by several teams of astronomers using facilities that included the Chandra, Lick, and Keck Observatories. In May 2007 NASA and several of the astronomers announced the first detailed analyses of the supernova, describing it as the “brightest stellar explosion ever recorded”. In October 2007 Quimby announced that SN 2005ap had broken SN 2006gy’s record as the brightest ever recorded supernova, and several subsequent discoveries are brighter still. Time magazine listed the discovery of SN 2006gy as third in its Top 10 Scientific Discoveries for 2007.
It occurred in a distant galaxy (NGC 1260), approximately 238 million light years away. Therefore, due to the time it took light from the supernova to reach Earth, the event occurred about 238 million years ago. Although at its peak the SN 2006gy supernova was intrinsically 400 times as luminous as SN 1987A, which was bright enough to be seen by the naked eye, SN 2006gy was more than 1,400 times as far away as SN 1987A, and too far away to be seen without a telescope.
It is classified as a type II supernova because it showed lines of hydrogen in its spectrum, although the extreme brightness indicates that it is different from the typical type II supernova. Several possible mechanisms have been proposed for such a violent explosion, all requiring a very massive progenitor star. The most likely explanations involve the efficient conversion of explosive kinetic energy to radiation by interaction with circumstantial material, similar to a type IIn supernova but on a larger scale. Such a scenario might occur following mass loss of 10 or more M☉ in a luminous blue variable eruption, or through pulsational pair instabilityejections.
Image: NASA / CXC / UC Berkeley / N.Smith
Text: Wikipedia contributors. “SN 2006gy.” Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 6 Dec. 2016. Web. 10 Aug. 2017.