A supernova leaves behind a compact object in a binary system

This artist’s impression shows the process by which a massive star within a binary system becomes a supernova. This series of events occurred in the supernova SN 2022jli, and was revealed to researchers through observations with ESO’s Very Large Telescope (VLT) and New Technology Telescope (NTT). After a massive star exploded as a supernova, it left behind a compact object — a neutron star or a black hole. The companion star survived the explosion, but its atmosphere became puffier as a result. The compact object and its companion star continued to orbit one another, with the compact object regularly stealing matter from the other’s puffy atmosphere. This accretion of matter was seen in the researchers’ data as regular fluctuations of brightness, as well as periodic movements of hydrogen gas.