A nearby supernova proves the existence of a neutron star at its center

When a star explodes as a type II supernova at the end of its life, it leaves behind a neutron star or black hole. But without knowledge of the progenitor star’s parameters and without direct observational data, we cannot be sure which objects remain in the extinct star’s place. However, an international team of scientists, using data from the James Webb Telescope, has discovered the first convincing evidence of the presence of a neutron star at the location of supernova SN 1987A. This could be seen with the naked eye from Earth. A supernova explosion is a spectacular event that occurs at the end of the evolution of some stars. During a flare, huge amounts of energy are released, the brightness of the star temporarily increases by several orders of magnitude, and material is ejected from the outer shell into the surrounding space. As a result, there may be a dwarf star, neutron star, black hole, or nothing left in the place of the progenitor star. Type II supernova SN 1987A is located in the Large Magellanic Cloud, a nearby satellite dwarf galaxy. It is the youngest known supernova in the Local Group of galaxies, and its light reached Earth exactly 37 years ago on February 23, 1987. The supernova was so bright and close that it could be observed with the naked eye. A few hours before SN 1987A was visually observed, neutrinos were detected by the LSD detector underground at Mont Blanc, indicating that a neutron star formed at the site of a protostar with a mass of at least eight suns. I did. However, the registration of neutrinos is only indirect evidence. At the same time, direct observation was not possible due to the dust generated after the explosion. That means we still don’t know what exactly remains at the site of the supernova explosion, whether it’s a neutron star or a black hole. So in a new study, an international group of astronomers examined the remains of supernova SN 1987A, based on observational data from the orbiting James Webb Observatory. Through infrared observations, scientists were able to find evidence of ionized argon and sulfur atoms near the progenitor star’s explosion site. The researchers report their observations and conclusions in a paper published in the journal Science. The study authors simulated different scenarios for the ionization of argon and sulfur in supernova remnants and found that there were only two possible causes. Electrons from the outer shell of the atom are knocked out (by may become an ion nebula). . In any case, the obtained data clearly indicate the presence of a neutron star at the center of the remnant SN 1987A. “Supernovae are thought to be the main source of chemical elements in the universe, so we would like to have a good model for supernovae.” There is no other neutron star like supernova SN 1987A. Supernova SN 1987A is very close to us and formed recently. “Additionally, the surrounding material is expanding at speeds of up to 10,000 kilometers per second, so we will likely see more details over time,” the study authors explained.

source: https://www.science.org/doi/10.1126/science.adj5796