Deaths of massive stars are the spectacular luminous explosions that can outshine entire galaxies and radiate more amount of energy than our sun ever will in its entire lifetime. These are well known as Supernovae. An average-sized supernova usually shines with the brightness of 10 billion suns and has a mass of 8 to 15 times the mass of the sun. But now, astronomers have identified the massive and brightest supernova we have ever seen. This supernova, named SN2016aps, is at least twice as bright and more energetic than any other supernovae. The star that produced this supernova was also extremely massive (50 to 100 times the mass of the Sun). This particular supernova was observed by the PanSTARRS Survey for Transients on 22 February 2016, in a galaxy 4.5 billion light-years from Earth. Astronomers have been studying it ever since. They believe it’s an example of a pulsational pair-instability supernova, and may have formed as the result of the merging of two massive stars prior to the explosion.
The total kinetic energy of SN2016aps was around 5×10^52erg, approximately equal with the famous 1998 hypernova SN1998bw, from a progenitor star 25 to 40 times the mass of the Sun. But the peak luminosity of SN2016aps is 4.3×10^44 erg, over 40 times brighter than SN1998bw’s 1×10^43erg peak luminosity. Even though massive stars usually eject most of their hydrogen before going supernova, the researchers have found high levels of hydrogen on SN2016aps. This is because of the fact that this big star was once two smaller stars that later merged.
“SN2016aps is spectacular in several ways,” said astronomer Edo Berger of Harvard University. “Not only is it brighter than any other supernova we’ve ever seen, but it has several properties and features that make it rare in comparison to other explosions of stars in the Universe”, he added.
In a typical supernova, the radiation is less than 1% of the total energy. But in SN2016aps, scientists found that the radiation was five times the explosion energy of a normal-sized supernova. This is the most light we have ever seen emitted by a supernova. Let’s hope we will get more news about this spectacular giant in the near future.
– Saifudheen
Source : University of Birmingham
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