Four Indian astronomers with foreign scientists trace rare supernova explosion

NEW DELHI: A team of four Indian astronomers, along with international collaborators, has tracked a rare supernova explosion and traced it to one of the hottest kind of stars called Wolf–Rayet stars ( WR stars ), which are highly luminous objects a thousand times that of the Sun .

WR stars are massive stars and strip their outer hydrogen envelope, which is associated with the fusion of Helium and other elements in the massive core. Tracking certain types of massive luminous supernovae explosion can help probe these stars that remain an enigma for scientists from across the world.

The four Indian scientists from the Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital , an autonomous institute under the Department of Science & Technology, and 16 scientists from different institutes in the US, UK, Canada, Ireland, Italy, Sweden and Korea have recently conducted the optical monitoring of one such stripped-envelope supernova called SN 2015dj hosted in the Galaxy NGC 7371, which was spotted in 2015. They calculated the mass of the star that collapsed to form the supernovae as well as the geometry of its ejection. The scientists also found that the original star was a combination of two stars – one of them is a massive WR star and another is a star much less in mass than the Sun.

The team presented the detailed optical evolution of SN 2015dj using data spanning up to 170 days after its discovery. Their discovery and detailed study were recently published in ‘The Astrophysical Journal .

Supernovae (SNe) are highly energetic explosions in the universe releasing an enormous amount of energy. Long-term monitoring of these transients opens the door to understand the nature of the exploding star as well as the explosion properties. It can also help enumerate the number of massive stars.

Long-term monitoring of these transients opens the door to understand the nature of the exploding star as well as the explosion properties. It can also help enumerate the number of massive stars.