Astrophysicists from Southern Methodist University (Texas, USA) found that the star that exploded in one of the galaxies close to the Milky Way was 200 times larger than the Sun. The energy of the supernova turned out to be comparable to the explosion of 100 million suns. The research results are published in The Astrophysical Journal.
According to scientists, the powerful flare was one of the closest to our galaxy in recent years. Astrophysicists recorded a supernova SN 2013ej on July 24, 2013. The exploded star was located in the spiral galaxy M74 in the constellation Pisces, which is located at a distance of 30 million light years from Earth.
Astrophysicists investigated the supernova using seven ground-based telescopes and the Swift spacecraft, which is designed to observe gamma-ray bursts. The observations lasted 450 days, during which scientists managed to establish the temperature of the supernova, the mass and radius of the exploding star, and the composition of the chemical elements.
The results showed that the star was 15 times the mass of the sun. Its temperature on the 10th day after the explosion reached 12 thousand degrees Celsius, and by the 50th day dropped to 4 thousand degrees. For comparison, the surface of the Sun has a temperature of 5.5 thousand degrees Celsius. The star most likely only lived for several tens of millions of years.
According to astrophysicists, the material of the star at the moment of the explosion was ejected at a speed of a thousand kilometers per second. Spectral analysis of SN 2013ej revealed many of the elements present in the material of the flared star: hydrogen, helium, calcium, titanium, barium, sodium, and iron.
Gamma-ray bursts are large-scale bursts of energy of an explosive nature observed in distant galaxies. They are powerful radiation emitted during supernova explosions. A gamma-ray burst that occurred in the Milky Way could sterilize the Earth, destroying all living organisms on it. Outbreaks like SN 2013ej, according to some scientists, can also destroy life in the galaxies where they occur.