Rare supernova explosion traced to hottest kind of star 'Wolf-Rayet'

Indian astronomers have tracked a rare supernova explosion and traced it to one of the hottest kinds of stars called 'Wolf-Rayet' or WR stars.

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, the Department of Science and Technology (DST) said in a statement.

The rare Wolf–Rayet stars are highly luminous objects a thousand times that of the sun and have intrigued astronomers for long. They are massive stars and strip their outer hydrogen envelope which is associated with the fusion of Helium and other elements in the massive core.

A team of astronomers from the Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital along with international collaborators have conducted optical monitoring of one such stripped-envelope supernova called SN 2015dj hosted in the galaxy NGC 7371 which was spotted in 2015, it said.

They calculated the mass of the star that collapsed to form the supernovae as well as the geometry of its ejection.

This work has been recently published in 'The Astrophysical Journal'.

The scientists also found that the original star was a combination of two stars, one of them is a massive WR star and another much less in mass than the sun, the statement added.