M31-2014-DS1

M31-2014-DS1 is a star that earlier was observed to be a very luminous yellow giant in Andromeda. It underwent a transient, brightening in 2014, then fading until 2022, after which no trace is seen. It has been of research interest, as a candidate for a core collapse that did not result in a core collapse supernova: the brightening was not as bright as a supernova would be. Such an event is sometimes termed a failed supernova. It presumably became a stellar-mass black hole. Within simulations, there has been a challenge to trigger supernova-strength explosions (a foe) through a core collapse, suggesting such collapses perhaps don't always produce an explosion. Also, I believe theory has hypothesized that within a certain mass range, a core collapse does not result in a supernova-strength explosion.