A red supergiant star that is 1,500 times larger than the sun is in its death-throes. Scientists rarely see the demise of such massive stars, and they stand to learn a lot from the data.
The largest known star in the galaxy, parked in a star cluster some 16,000 light-years away, has exhausted its hydrogen fuel and is shedding gas in a signal that the end is near – at least on cosmic timescales.
The star, a red supergiant, is surrounded by clouds of glowing hydrogen, providing a rare opportunity to observe a massive star during such an early stage in its prolonged demise – a path slated to end with the star's catastrophic collapse and the subsequent explosion at its core, known as a supernova.
Such explosions seed the galaxy with chemical elements heavier than hydrogen and helium. These elements form in the fusion furnaces at the heart of stars. The elements get ejected into interstellar space by stellar winds as well as by events that occur at the end of a star's life. They become the raw material for building other objects in the cosmos – from planets to people.
Studying gas clouds such stars release as they lose mass can yield insights into the physical processes at work as well as clues as to the kind of compact object – a neutron star, or perhaps a black hole – the star's core could become after its explosive end.