Indian astronomers have tracked a rare supernova explosion and traced it to one of the hottest kind of stars called Wolf–Rayet stars or WR stars.
Q What are Wolf–Rayet Stars?
Wolf-Rayet stars represent a final burst of activity before a huge star begins to die.
These stars, which are at least 20 times more massive than the Sun, “live fast and die hard”.
Wolf-Rayets stars are divided into 3 classes based on their spectra, the WN stars (nitrogen dominant, some carbon), WC stars (carbon dominant, no nitrogen) and WO where oxygen is in dominant quantities.
The average temperature of a Wolf-Rayet star is greater than 25,000 Kelvin, and they can have luminosities of up to a million times that of the Sun.
Q What have Indian researchers studied?
Indian astronomers have 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.
Q What are their findings?
The scientists 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.
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.