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.
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 —…
