Betelgeuse, the bright red star marking Orion’s shoulder, is the star most often cited as the next likely supernova visible from Earth. It’s a red supergiant in the late stages of burning through its nuclear fuel, and recent research suggests it could explode within the next few hundred to a few thousand years. Several other massive stars are also on the short list, but Betelgeuse combines proximity, size, and an advanced evolutionary stage in a way no other candidate quite matches.
Why Betelgeuse Tops the List
Stars need to be at least 8 to 10 times the mass of our Sun to end their lives as supernovae. Betelgeuse clears that bar easily, weighing in at roughly 15 to 20 solar masses. Like all massive stars, it started by fusing hydrogen into helium, then moved on to fusing helium into carbon. What makes Betelgeuse special is that multiple lines of evidence now suggest it has reached the carbon-burning phase, one of the final steps before core collapse.
A 2023 study by Hideyuki Saio and collaborators analyzed four distinct pulsation cycles in Betelgeuse, ranging from a 185-day rhythm to a longer 2,200-day cycle. All four could be explained by a “breathing” star in the late stages of carbon burning. If that interpretation is correct, the timeline shrinks dramatically. Once carbon is exhausted in the core, a supernova is expected within a few tens of years. The researchers estimate carbon exhaustion is probably less than a few hundred years away, putting the explosion within roughly 1,000 years rather than the commonly cited 100,000.
That said, pinning down exactly how much carbon remains in the core isn’t currently possible. The traditional estimate of “sometime in the next 100,000 years” reflects genuine uncertainty, not a lack of interest. Betelgeuse sits about 650 light-years from Earth, close enough that its explosion would be spectacular (briefly rivaling the full Moon in brightness) but far too distant to pose any danger to life on our planet.
The Great Dimming of 2019–2020
In late 2019, Betelgeuse began fading dramatically. By early February 2020, it was the faintest it had been in nearly two centuries of recorded observations. Headlines speculated that the star was on the verge of exploding. The real explanation turned out to be less dramatic but still remarkable: a massive eruption from the star’s surface launched a cloud of hot gas more than a hundred million miles wide, carrying as much material as the star normally sheds in an entire year through its stellar wind. As that gas moved outward and cooled, it condensed into dust that blocked a significant portion of Betelgeuse’s light.
This “surface mass ejection” was not a sign of imminent collapse, but it wasn’t trivial either. More than four years later, Betelgeuse remains in an unstable state. The event offered astronomers an unprecedented look at how red supergiants behave in the centuries or millennia before they die.
Other Strong Candidates
Antares
Antares, the ruddy heart of Scorpius, is essentially Betelgeuse’s twin in terms of supernova potential. It’s a red supergiant with about 12 times the Sun’s mass, a radius 680 times that of the Sun, and a luminosity nearly 76,000 times greater. At roughly 550 light-years away, it’s one of the two nearest red supergiant supernova progenitors (the other being Betelgeuse). Antares is somewhat less massive, and there’s less evidence that it has reached as advanced a burning stage, so most astronomers place it slightly behind Betelgeuse in the “next to blow” rankings. But “slightly behind” could still mean it goes first. These timelines carry enormous uncertainty.
Eta Carinae
Eta Carinae is a different beast entirely. It’s a binary system located about 7,500 light-years away in the southern constellation Carina. The primary star is a luminous blue variable with roughly 90 solar masses, making it one of the most massive stars known in our galaxy. Its companion adds another 30 solar masses. Stars this heavy don’t just go supernova; they can produce hypernovae, explosions roughly ten times more energetic than a standard supernova. Eta Carinae is famous for a violent eruption in the 1840s that briefly made it the second-brightest star in the sky and expelled massive clouds of gas that are still visible today as the Homunculus Nebula. It’s a guaranteed future supernova, but its greater distance and different evolutionary path make it harder to compare directly with Betelgeuse on a timeline.
Rigel
Rigel, the blue-white star anchoring Orion’s foot, is often overlooked in supernova discussions because it doesn’t look “old” the way a red supergiant does. But at about 17 solar masses, it comfortably exceeds the supernova threshold. Rigel is a blue supergiant, meaning it’s at an earlier evolutionary stage than Betelgeuse. It will likely swell into a red supergiant before eventually collapsing, or it may explode while still blue (blue supergiants can and do go supernova, as SN 1987A demonstrated). Either way, its explosion is probably millions of years further out than Betelgeuse’s.
Spica
Spica, the brightest star in Virgo, is a binary system with a primary star roughly 12 times the Sun’s mass. That puts it right at or above the supernova threshold. It’s about 250 light-years from Earth, which would make its eventual explosion one of the closest supernovae in recorded history. However, Spica is still on the main sequence, fusing hydrogen in its core, so its supernova is millions of years away.
A Different Kind of Explosion: Type Ia Candidates
Not all supernovae come from massive stars collapsing under their own gravity. A second type happens in binary systems where a dense stellar remnant called a white dwarf accumulates material from a companion star. When the white dwarf reaches about 1.4 times the mass of the Sun, runaway nuclear fusion detonates the entire star. These “Type Ia” supernovae are just as bright and destructive as core-collapse events.
IK Pegasi is the closest known candidate for this type. The system contains a white dwarf orbiting a normal star about 150 light-years from Earth. Recent research suggests IK Pegasi-type systems may follow a “double-merger pathway,” where earlier interactions in a multi-star system create the conditions for an eventual thermonuclear explosion. This process unfolds over a very long timescale, so IK Pegasi isn’t expected to explode anytime soon, but it’s a noteworthy entry on the list of nearby supernova candidates.
How We’d Know It’s Coming
A supernova doesn’t happen without warning at the subatomic level. In the final hours before core collapse, a dying star releases a flood of neutrinos, nearly massless particles that pass through ordinary matter almost undetected. Current and planned neutrino detectors can pick up this “pre-supernova” signal. The proposed RES-NOVA experiment, for example, could detect pre-supernova neutrinos from a star up to about 1,500 light-years away, providing roughly 10 seconds of advance warning before the main explosion’s neutrino burst arrives. That’s not much time for humans, but it’s enough for automated telescopes worldwide to swivel toward the source and capture the very first moments of a supernova, something never observed before.
For a star like Betelgeuse, the neutrino signal would be unmistakable. Every major neutrino observatory on Earth would light up simultaneously, giving astronomers certainty that the explosion was underway before any visible light reached us.
Is Earth in Any Danger?
A supernova would need to occur within roughly 25 to 50 light-years of Earth to seriously damage the ozone layer and threaten life. Betelgeuse is about 650 light-years away. Antares is about 550. Eta Carinae is 7,500. None of the known supernova candidates are anywhere close to the danger zone. When Betelgeuse does explode, it will be a spectacular naked-eye event lasting weeks or months, visible even during the day. It will be the astronomical event of the millennium, not a threat.