One of the most intriguing stars in our universe, WOH G64, has scientists buzzing. This enormous red supergiant resides in the Large Magellanic Cloud, about 160,000 light-years away. At more than 1,500 times the sun’s radius, WOH G64 is a giant by any measure.
Between 2013 and 2014, astronomers witnessed something extraordinary. The star seemed to change from a classic red supergiant to a hotter, yellower state. A team led by Gonzalo Muñoz-Sanchez from the National Observatory of Athens suggested that this might signal a shift into a rare yellow hypergiant phase. This could hint at its upcoming transformation into a supernova.
Their findings, posted on arXiv in November 2024, described significant changes: the star got hotter, shrank to about 800 solar radii, and its atmospheric chemistry shifted. They also noticed a hot companion star interacting with WOH G64, adding complexity to this cosmic drama.
However, recent observations tell a different story. New studies indicate WOH G64 might never have left its red supergiant phase at all. Red supergiants evolve from massive stars that are exhausting their nuclear fuel, causing them to puff up significantly. They are known for their instability, often undergoing dramatic changes in brightness or color.
In a January 2026 study published in the Monthly Notices of the Royal Astronomical Society, researchers found titanium oxide in WOH G64’s atmosphere, which contradicts the idea that it’s in a hypergiant state. “These new findings suggest WOH G64 is still a red supergiant,” says astronomer Jacco van Loon.
Similar behavior has been observed in other stars. For instance, Betelgeuse famously dropped in brightness by nearly 25% in 2020, creating quite a stir. Such fluctuations don’t always mean a star is on the brink of destruction; often, they’re just part of a supergiant’s chaotic lifecycle.
There’s also a growing consensus about WOH G64’s binary companion. The interplay between the two stars might be causing these peculiar changes. This suggests that the environment around them can produce variations that look like major evolutionary shifts without an actual transformation.
Ongoing observations of WOH G64 are essential. They will help scientists understand whether the star is on the cusp of a major change or if its current behavior is simply how it naturally behaves.
At its core, WOH G64 remains a mystery, full of surprises that keep astronomers engaged. As they continue to monitor it, we may uncover more about the life cycles of these massive stars—and potentially what hints they give us about the eventual fate of all stars. The original paper by Muñoz-Sanchez and his team is available in Nature Astronomy.
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