One of the biggest known stars may be approaching the final stage of its life – a supernova

A new study published in Nature Astronomy provides evidence that WOH G64, one of the largest known stars in the Large Magellanic Cloud, has transitioned from a red giant to a rare yellow superstar — a transition that may indicate a final and violent phase in its life.

The giant star, WOH G64, one of the largest and strangest stars known today, has undergone a dramatic change in recent years that may indicate that it has entered one of the last and rarest stages in the evolution of massive stars. A new study published inNature Astronomy  suggests that the star, which for decades was considered an extreme red giant in the Large Magellanic Cloud, has likely entered the yellow supergiant phase – a brief, unstable phase that may precede a supernova, but does not guarantee that it will occur immediately. (Nature)

 WOH G64 resides in the Large Magellanic Cloud, a satellite galaxy of the Milky Way, and has been known to astronomers since the 70s as a particularly unusual object: very bright, shrouded in dust, and with a radius more than 1,500 times that of the Sun, according to the description in the new study. As early as 2024, astronomers were able to image it using the European Southern Observatory's Very Large Telescope interferometer, thus obtaining the first close-up image of a star outside our galaxy. The image revealed a thick envelope of gas and dust around the star, evidence that it is losing mass at a rapid rate. (eso.org )

According to the study, the main turning point occurred around 2013–2014. Analysis of photometric observations over about 30 years and multi-period spectroscopy showed a sharp but gradual change in the star's behavior: from semi-periodic variability typical of a red giant, to irregular behavior and spectral signatures more consistent with a hotter object. The researchers conclude that WOH G64 is likely a rare massive symbiotic system, in which the component that was a red giant transitioned to a yellow superstar state, with a hot B-type companion star alongside it.

The end of massive stars

The significance of this transition is very important for understanding the fate of massive stars. Red supergiants are a late stage in the life of massive stars, but not all of them go through the yellow hypergiant phase. When such a transition occurs, it may indicate that the star is losing its outer layers, its core is contracting, and it is approaching a violent final stage. However, the researchers themselves are careful not to declare an immediate supernova. The paper proposed three possible explanations for the change: a binary interaction that caused the star's envelope to be partially removed, a return to a quiescent state after a long outburst that lasted more than 30 years, or a pre-supernova "superwind" phase in which outer layers are rapidly ejected. Only the third scenario directly supports the idea that the explosion is already approaching. (arXiv)

If this is indeed a pre-supernova phase, WOH G64 gives astronomers a very rare opportunity to observe in near real time a brief transitional stage in the life of a very massive star. Most processes of stellar evolution last for vast periods of time, making it difficult if not impossible to follow a profound change in a human lifetime. Here, however, the picture is different: in just a few years, the appearance of one of the most extreme stars known has changed. This may help solve an open question in astrophysics — how exactly the most massive stars end their lives, and whether some go through hot intermediate stages before collapsing. (natureasia.com)

"Soon" could also mean hundreds of years.

There is also reason for media caution. The headlines talk about a star “about to explode,” but scientifically it is more accurate to say that the star is showing signs consistent with a rare final evolutionary stage, which could end in a supernova. Astronomers know that such a star will not live for billions of years like the Sun, but it is still very difficult to determine whether “soon” means years, centuries, or more. So the real importance of the study is not just the possibility of a future celestial spectacle, but that it provides a rare vantage point for understanding how massive stars lose mass, are affected by a companion star, and approach their end.

The article, titled: “The dramatic transition of the extreme red supergiant WOH G64 to a yellow hypergiant”, was published on February 23, 2026 inNature Astronomy . It reinforces the idea that at least some extreme red giants do not collapse directly from the familiar “cold” state, but may undergo a hot and violent intermediate stop. If WOH G64 does indeed continue on this trajectory, it may become one of the most intriguing supernovae ever studied in years or generations to come—but even before that, it already provides a rare lesson in the life and death of an extreme star. (Nature)

More of the topic in Hayadan:

• Discovery of interstellar embryos again. This time in the Small Magellanic Cloud
• Researchers discovered: Massive stars in metal-poor galaxies are also born in pairs
• The Large Magellanic Cloud: Star mapping changes our view of a nearby galaxy
• Suns similar to our Sun have been discovered when it was young in the Small Magellanic Cloud galaxy
• The Webb Space Telescope reveals star formation in the dusty bands of the Small Magellanic Cloud