Scientists identify an entirely new type of supernova

An international team of researchers recently identified an unprecedented type of starburst, which has been predicted to exist for nearly 40 years. Known as an “electron-capturing supernova,” it also solves a stubborn medieval mystery.

A third type of starburst

In the year 1054, many observers around the world reported the appearance of a bright light in the sky, visible during the day for more than three weeks and at night for about two years. As part of the work presented in the magazine natural astronomy, an international team of researchers confirmed that the event, is still visible today in the form of ” Crab Nebula A supernova was capturing an electron.

Astronomers have been speculating for decades about the existence of this third type of starburst, which is believed to have arisen from massive stars in the super asymptotic branch of giants (SAGB). baptized SN 2018zd, The first example of such a cosmic phenomenon has been discovered within the galaxy NGC 2146, about 31 million light-years from tr.

There are two main types of stellar explosions. They are called thermonuclear supernovae, the first involving the explosion of a white dwarf The presence of accumulated material from a companion in a binary system. As the seconds feature the collapse of the iron core of a massive star that finds itself short on fuel, leaving behind a Black hole or a neutron star.

Similar to a mixture of the two, the newly described new type of supernova occurs when a star is discovered to be massive enough for its core to collapse, but too light for the elements it contains to fuse and form. life span.

Six of the main characteristics predicted by the theory

team led by Daiichi Hiramatsu, From’University of California, I found it SN 2018zd It exhibited six of the main properties predicted by theory, including a large loss of mass before the explosion, an unusual stellar chemical composition, a weak explosion, low radioactivity as well as a neutron-rich core.

Archive footage from Hubble’s spatial telescope Before the explosion it also showed that the progenitor star was similar to the stars SAGB.

« We first wondered what this strange phenomenon was, then looked at all aspects of SN 2018zd and realized that they could all be explained in an electron capture scenario. “, and concludes Hiramatsu.