A long-anticipated cosmic explosion has finally happened. Researchers have discovered evidence for an electron-capture supernova. This occurs when atomic nuclei in a star’s core absorbs electrons and explode.
The occurrence was predicted for the first time in 1980. But scientists have never been sure that they had witnessed any. Supernova 2018zd, a flare that flashed in the sky in 2018, matches many expected features of the blasts, as per scientists in Nature Astronomy in June.
Electron-capture supernovas are the result of stars on the point of explosion. A supernova occurs when nuclear fusion takes place in the core of a star with a mass greater than 10 times that of the sun halt and the star can no longer support itself against gravity.
The star’s outer layers blast outward as the core falls inward and eventually rebounds. Smaller stars, fewer than about eight solar masses can resist collapse and become a dense entity known as a white dwarf.
However, there is a poorly understood middle-ground for stars between the masses of 8 and 10 solar masses.
Scientists have long suspected that electron-capture supernovas will occur for some stars in that range. When electrons are packed densely together, they start to move quicker, as per quantum physics. Those spinning electrons exert a force that opposes gravity’s inward pull.
However, if inner reactions within a star reduce the number of electrons, that support is weakened. If the star’s core collapses and an electron-capture supernova occurs. Finding more of these supernovas can lead to the discovery of their progenitors, odd-mass stars in the middle of the mass spectrum.
It may also help scientists in finding the difference between stars that will not explode. Further the data may indicate how often these odd supernovas occur, which is crucial information for understanding how supernovas.
