Astronomers at the LIGO and Virgo detectors have recorded gravitational waves occurring in the same region of the sky as the ageing red supergiant star Betelgeuse. The gravitational wave candidate is catalogued as S200114f, and the news has made some astronomers and space enthusiasts take to social media to discuss whether it’s related to Betelgeuse’s dimming in brightness over the past month or so.
The detection has even led some to wonder whether the gravitational waves could actually be related to Betelgeuse itself, as it has been known for some time that the star is due to explode.
Betelgeuse is easy to spot in the night sky during winter, as it forms the left shoulder (from Earth’s perspective) of the constellation Orion, the hunter.
The star is about 12 times the mass of our Sun and is nearing the end of its life. When supergiant stars like Betelgeuse use up their fuel, they no longer have the energy to counter their own gravity, and so they collapse.
They explode in a phenomenon known as a supernova, and it’s thought that Betelgeuse is relatively close to reaching this stage of its life. It could explode this week, or it could explode in a million years.
— LIGO (@LIGO) January 14, 2020
Above: a Tweet by the LIGO team announcing the gravitational wave detection
However, a Betelgeuse explosion is probably not the reason for this latest detection of gravitational waves.
Gravitational waves are ripples in space-time generated by violent, energetic processes occurring in space, and were first predicted by Albert Einstein in 1916 in his general theory of relativity.
So far gravitational waves have been observed as an effect of massive objects colliding, such as a pair of black holes or a pair of neutron stars, or a black hole and a neutron star.
They have been successfully detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in the US and the Virgo interferometer in Italy.
And while the latest candidate for gravitational waves may be unrelated to the life cycle of the star Betelgeuse, both subjects are going to be worth keeping an eye on in years to come.