The brightest star in our galaxy can explode as a supernova at any moment, but it is not Betelgeuse

WOH G64 – a “living” example of pre‑supernova evolution of a red supergiant

In the Large Magellanic Cloud, a satellite of the Milky Way at a distance of about 160,000 light years, lies one of the brightest and most unusual stars – WOH G64. Since its discovery in the late twentieth century, scientists have noted that it differs from ordinary red supergiants not only in size but also in rapid changes that may indicate an impending explosion.

Key facts
Parameter Value
Radius over 1,500 times larger than the Sun’s radius
Luminosity hundreds of thousands of times higher than the Sun’s luminosity
Age less than 5 million years (critically young for a star)
Class red supergiant with a dense dust shell that strongly dims visible light

Observed changes
* 2013–2014:
* The star dimmed.
* Its surface temperature rose by more than 1,000 °C and its spectrum turned yellow.

Scientists believe this is a transition from the red supergiant phase to a rare yellow hypergiant stage. Such a transformation is accompanied by intense mass loss of outer layers – possibly due to internal pulsations or interaction with a companion in a binary system.

New observations 2024
Using the VLTI interferometer (Very Large Telescope Interferometer) in Chile, the first detailed image of WOH G64 outside the Milky Way was obtained. The image confirmed:

* A strong outflow of material.
* An unusual shape of the dust shell.

This information strengthens the hypothesis of an unstable and short yellow hypergiant phase that usually precedes core collapse and a Type II supernova explosion.

Why it matters
* Real-time observation of evolution: WOH G64 is a rare case where rapid changes can be tracked in “living” time.
* Prediction of future explosion: Exact timing is unknown (could be decades, centuries or millennia), but current signs suggest the final stage is approaching.
* Scientific prospects: If a supernova occurs in the foreseeable future, it will become the brightest astronomical event in the neighboring galaxy and allow study of mass‑loss mechanisms in massive stars.

Observations continue with ground‑based and space telescopes to monitor further changes in brightness and spectrum. The case of WOH G64 highlights how dynamic the final stages of life for the most massive stars in the Universe can be.