Betelgeuse Supernova: When Will Betelgeuse Explode?

When will Betelgeuse go supernova?

This is the question everyone asks, and the honest answer is that astronomers cannot give a date. Betelgeuse is a massive star, roughly 11 to 20 times the mass of the Sun, that has already used up the hydrogen in its core and swollen into a red supergiant. Stars like this end their lives when their core runs out of usable fuel, collapses in a fraction of a second and drives a huge explosion called a core-collapse (Type II) supernova.

The difficulty is working out how far along that path Betelgeuse is. Most estimates put the explosion somewhere within the next 100,000 years. Several recent studies conclude the star is still burning helium in its core, a long and stable phase, which would push the supernova tens of thousands of years or more into the future. A few researchers have argued it could be closer to the final stages, but that view is a minority one. On a human timescale, the chance of seeing the Betelgeuse supernova in your lifetime is very small, though not zero.

One thing that would give us warning: in the final hours before the visible explosion, the collapsing core releases a flood of neutrinos. Neutrino detectors around the world, linked through the Supernova Early Warning System (SNEWS), would pick these up first, giving astronomers a head start of several hours.

What would the Betelgeuse supernova look like?

It would be the brightest stellar event in recorded history. Models of a Type II supernova at Betelgeuse’s distance suggest a peak brightness somewhere around magnitude −8 to −12. To put that in context:

That means a single point of light roughly as bright as a quarter to half Moon, bright enough to cast shadows at night and to be seen easily in daylight. It would stay near peak brightness for around three months, remain visible to the naked eye for a year or more and then fade slowly. Because Betelgeuse is close to the celestial equator, the whole world would see it, from the Arctic to almost all of Antarctica. Afterwards Orion would look permanently different, with an empty space where its shoulder used to be.

Is the Betelgeuse supernova dangerous to Earth?

No. Betelgeuse is roughly 500 to 650 light-years away; different methods give different values, and many sources quote about 550 to 650 light-years. A supernova would need to be within about 50 light-years to strip away a significant part of Earth’s ozone layer. Betelgeuse is around ten times farther than that, so the explosion would be a spectacular sight and a scientific goldmine, not a threat. It is also not the kind of star expected to produce a gamma-ray burst aimed at Earth.

Will Betelgeuse become a black hole?

Probably not. After the explosion, the collapsed core of the star is left behind. For stars of Betelgeuse’s estimated mass, the usual outcome is a neutron star: an object about 20 km across with more mass than the Sun. A black hole forms when the core is too massive even for a neutron star to hold up, which needs a heavier star than most estimates allow for Betelgeuse. So a black hole is not impossible, but a neutron star is the much likelier result.

How big is Betelgeuse?

Betelgeuse is one of the largest stars visible to the naked eye. Its radius is usually given as about 700 times the Sun’s, with published estimates ranging from roughly 640 to over 1,000 solar radii, partly because the star has no sharp edge and its outer layers pulse in and out. If you put Betelgeuse where the Sun is, its surface would swallow Mercury, Venus, Earth and Mars and reach into the asteroid belt, possibly as far as Jupiter.

Despite its size, Betelgeuse is not very dense: its outer layers are a thin, cool gas at about 3,500 kelvin (roughly 3,200 °C), which is why it glows orange-red. It is also extremely luminous, giving out tens of thousands of times more light than the Sun. Even so, it is a young star by cosmic standards, only around 10 million years old, compared with the Sun’s 4.6 billion years. Massive stars live fast and die young.

The Great Dimming: was Betelgeuse about to explode?

Betelgeuse always changes in brightness, with a main cycle of about 400 days and a much longer cycle of about 2,100 days. But from October 2019 to February 2020 it faded far more than usual, dropping to around magnitude 1.6 and losing more than half its normal brightness. Orion looked visibly lopsided, and the internet filled with predictions that a supernova was imminent.

It wasn’t. Observations with the Hubble Space Telescope and the European Southern Observatory’s Very Large Telescope showed that the star had thrown off a huge burst of hot gas from its surface. As that gas moved away and cooled, it formed a dust cloud that blocked part of the star’s light from our point of view. Betelgeuse recovered, and by 2023 it was brighter than normal. The Great Dimming was a sign of an unsettled, ageing star, not of an explosion about to happen.

Siwarha: Betelgeuse’s hidden companion

The biggest Betelgeuse news of the last two years is that it is not alone. Astronomers had long suspected that the star’s 2,100-day brightness cycle was caused by a smaller star in orbit around it. In July 2025, a team using the ’Alopeke camera on the Gemini North telescope reported the first probable direct image of this companion, very close to Betelgeuse and several magnitudes fainter. In September 2025 the International Astronomical Union approved its name: Siwarha, from Arabic for “her bracelet”.

In January 2026, a study led by Andrea Dupree of the Center for Astrophysics | Harvard & Smithsonian, using Hubble and ground-based telescopes over almost eight years, found the “wake” the companion carves through Betelgeuse’s extended atmosphere as it orbits roughly every six years. Radio studies reported in autumn 2026 also point to the companion disturbing the star’s outer gas. Siwarha is currently hard to see because of its position in the orbit; astronomers expect the next good opportunity to study it when it is farthest from Betelgeuse in our view, around November 2027.

The companion does not change the basic forecast: Betelgeuse will still end as a supernova on a timescale of many thousands of years. But it explains some of the star’s odd behaviour and gives astronomers a new way to measure Betelgeuse’s mass, which is key to predicting exactly how and when it will die.

How to find Betelgeuse tonight

Betelgeuse is one of the easiest bright stars to find. Look for Orion and its belt of three stars in a short straight line. From the Northern Hemisphere, Betelgeuse is the bright orange star above and to the left of the belt, marking Orion’s shoulder; bluish Rigel sits below and to the right. From the Southern Hemisphere the picture is upside down, so Betelgeuse appears below the belt. Its colour is the giveaway: compare it with white Rigel and Sirius and the orange tint is obvious, even from a city.

Betelgeuse is a star of the northern winter and southern summer evenings. Because the stars rise about four minutes earlier each night, it moves into the evening sky over the next few months. Times below were calculated for mid-latitudes such as New York, Los Angeles, London and New Delhi (local time; they differ by only a few minutes between these cities):

From New York it climbs to about 57° above the southern horizon, from Los Angeles about 63°, from London about 46° and from New Delhi about 69°. By April and May it sinks into the western twilight, and from about June to early July it is too close to the Sun to see. For the exact times where you are, use the live tool at the top of this page, or check which constellations are visible tonight and the Live Sky AR camera to point your phone at it.

Betelgeuse meaning and pronunciation

The name comes from Arabic. It is usually traced to yad al-jawzā’, “the hand of al-Jawzā’”, the name of the giant figure the constellation represented; a medieval misreading of one letter in Latin translations is thought to have turned it into “Bet-” and then Betelgeuse. In English, both “BET-el-jooz” and “BEET-el-jooz” are common. Its catalogue name is Alpha Orionis, even though Rigel is usually the brighter of the two. And yes, it is the star whose name inspired the title of the film Beetlejuice.

Frequently asked questions

Sources: STScI/NASA: Hubble helps detect the wake of Betelgeuse’s companion (Jan 2026); ScienceDaily: Betelgeuse has a hidden companion (Jan 2026); Star Walk: Will Betelgeuse go supernova? (Oct 2026); Betelgeuse overview and references. Positions and times on this page are calculated by SpaceTracker.live with the Astronomy Engine library.