A team of scientists from the Las Cumbres Observatory (USA) has discovered the first convincing evidence of a new type of stellar explosion: an electron-capturing supernova, Nature Astronomy published Monday.
Experts estimate that these supernovae originate from massive explosions of the Super-Converging Giant Branch (SAGB), the research indicates.
The Astronomy scientists They knew two main types of supernovae. One is thermonuclear: the explosion of a white dwarf star after gaining material in a binary star system.
The other is an iron core collapse supernova in which a massive star (more than 10 times the mass of the Sun) runs out of nuclear fuel and its iron core collapses, resulting in a black hole or neutron star.
Meanwhile, electron-capturing supernovae lie on the boundary between these two types of supernovae. Stars stop merging when their cores are made of oxygen, neon, and magnesium. It is not massive enough to form iron.
In an electron-capturing supernova, some electrons from the oxygen, neon, and magnesium nuclei collide with their atomic nuclei (a process called electron capture).
The study indicates that this removal of electrons causes the star’s core to bend under its own weight and collapse, resulting in an electron-capturing supernova.
If the star is a little heavier, the central elements can fuse to form heavier elements, extending its life.
The study was led by Daiichi Hiramatsu, a graduate student from the University of California, Santa Barbara (UCSB) and the Las Cumbres Observatory (LCO).
Hiramatsu is a member of the so-called global supernova project, which was formed by Scientists Around the world, using dozens of telescopes around the world and above.
The team discovered that the SN 2018zd supernova has many unusual features, some of which were first seen in a supernova.
A supernova is relatively close, only 31 million light-years away, in the galaxy NGC 2146.
This allowed the team to examine archival images taken before the Hubble Space Telescope exploded and discover the possible progenitor star.
The observations were consistent with another SAGB star recently identified in Milky Way, but inconsistent with models of red giant planets, the ancestors of supernovae with a normal iron core collapse.