Observation of the red supergiant star, Betelgeuse, revealed a vast plume of gas almost as large as our Solar System and a gigantic bubble boiling on its surface. In 2019–2020, a great plume of material erupted from Betelgeuse. A recent brightening event in 2023 suggested that a supernova might be imminent, so what will we see when it finally happens? (Credit: ESO/L. Calçada)

This is what we’ll see when Betelgeuse goes supernova

The closest known star that will soon undergo a core-collapse supernova is Betelgeuse, just 640 light-years away. Here’s what we’ll observe.

Ethan Siegel
9 min read2 days ago

The stars in the night sky, as we typically perceive them, are normally static and unchanging to our eyes. Sure, there are variable stars that brighten and fainten, but most of those do so periodically and regularly, with only a few exceptions. One of the most prominent exceptions is Betelgeuse, the red supergiant that makes up one of the “shoulders” of the constellation Orion. Over the past five years, not only has it been fluctuating in brightness, but its dimming in late 2019 and early 2020, followed by a strange brightening in 2023, indicates variation in a fashion never before witnessed by living humans.

Betelgeuse is typically the 10th brightest star in our sky, but fell out of the top 20 during its faintest in 2020 and rose as high as the 7th brightest in 2023. As a red supergiant, it’s only a matter of time before it undergoes a core-collapse supernova, although no one known how to predict when that will occur. There’s no scientific reason to believe that Betelgeuse is in any more danger of going supernova today than at any random day over the next ~100,000 years or so, but many of us —…

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Starts With A Bang!
Starts With A Bang!

Published in Starts With A Bang!

The Universe is out there, waiting for you to discover it.

Ethan Siegel
Ethan Siegel

Written by Ethan Siegel

The Universe is: Expanding, cooling, and dark. It starts with a bang! #Cosmology Science writer, astrophysicist, science communicator & NASA columnist.

Responses (17)

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With my luck, I'd best attend to my cataract surgery sooner rather than later.

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I always learn so much from you! Thanks for making science and astronomy more accessible.

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I am always impressed, actually in awe, of your capacity to describe astronomical phenomena with such clarity. In this case it is sort of a capstone on Betelgeuse, which I first learned a bit about in a 1957 Astronomy class.
Thanks for sharing your gift.

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