News Brief: Latest supernova is also super-brightest
On July 8, astronomers reported sighting the brightest stellar explosion on record. First detected on June 14, it briefly shone with the light of roughly 600 billion suns. That’s about five times as powerful as the previous record holder.
Stars are born, grow old and die. For many large stars, one of the last stages in their life history is a huge blow-up. Astronomers refer to this catastrophic explosion as a supernova.
Subo Dong of the Kavli Institute for Astronomy and Astrophysics at Peking University headed a team of scientists who reported the new stellar fireworks in The Astronomer’s Telegram.
The star actually exploded about 2.8 billion years ago. But it was so far away that it has taken all of this time for its light to reach Earth. The star had been living in a galaxy that sits in the constellation Indus. (This constellation, first described in the late 1500s, was believed to outline a man holding arrows in both of his hands.)
The new outburst has been named ASASSN-15lh. It appears to be part of a class of “superluminous supernovas.” But the cause of such extraordinarily powerful explosions remains very much a mystery.
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astronomer Scientist who studies celestial objects, space and the physical universe as a whole.
constellation Patterns formed by prominent stars that lie close to each other in the night sky. Modern astronomers divide the sky into 88 constellations, 12 of which (known as the zodiac) lie along the sun’s path through the sky over the course of a year. Cancri, the original Greek name for the constellation Cancer, is one of those 12 zodiac constellations.
galaxy A system of stars, planets, and dust formed by gravitational attraction.
star A huge ball of gas, with its heat generated by nuclear fusion. Stars are held together by the force of gravity.
sun The familiar term given to the star nearest to Earth. It resides 150 million kilometers from Earth. In a sense, however, every star is a sun somewhere.
supernova (plural: supernovae or supernovas) A massive star that suddenly increases greatly in brightness because of a catastrophic explosion that ejects most of its mass.
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Original Journal Source: S. Dong et al. Follow-up observations of ASASSN-15lh establish it as the most luminous supernova ever discovered. The Astronomer’s Telegram. July 9, 2015.
Learn more about “supernovae” in this NASA backgrounder on its Imagine the Universe website. January 2011.