- Is a Gravitational Wave Detection Near Betelgeuse a Sign the Star is Ready to Explode?
by , https://www.cbc.ca/
At the end of its life, the enigmatic star will shine like a beacon in the sky
First it was the strange dimming of Betelgeuse. Now it’s a gravitational wave that once again has astronomers scratching their heads over this enigmatic star found in the constellation Orion. Betelgeuse has been grabbing a few headlines lately, as the normally bright star dimmed to its lowest point ever recorded — and astronomers don’t exactly know why.
Now the U.S.-based Laser Interferometer Gravitational-Wave Observatory (LIGO) has detected a gravitational wave coming from that direction, adding another intriguing detail to what’s happening. The first gravitational wave ever recorded — a powerful ripple through space-time caused by cataclysmic events, like two merging black holes — was detected in September 2015.
Since then, many more have been found, including one resulting from the merger of two black holes, as well as one from a binary neutron star merger. (A potential black hole-neutron star detection is still waiting to be confirmed.)
But seeing as Betelgeuse is still there, a source for the newly detected gravitational wave is unknown. Normally, Betelgeuse is a bright red star found in the left “shoulder” of Orion. It’s classified as a semi-regular variable star, meaning that it dims periodically, but not on a regular basis. (It has two periods when it dims: roughly once every 430 days and once every six years.)
During each cycle, dark spots appear on the surface of Betelgeuse, similar to the sunspots sometimes seen on the sun, but far, far larger.