Mysterious Shift in Giant Star Hints at Impending Supernova

Observations of the red supergiant WOH G64 suggest it may be shedding its outer layers and entering a new phase before a potential explosion.

Published on Mar. 4, 2026

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Astronomers have observed a dramatic shift in the behavior and appearance of the red supergiant star WOH G64, located in the Large Magellanic Cloud. Around 2014, the star suddenly became much bluer and warmer, transitioning from a cool red supergiant to a warmer, short-lived phase resembling a yellow hypergiant. This change in the star's properties could signal that it is shedding its outer layers and nearing the end of its life, potentially leading to a supernova explosion.

Why it matters

The study of WOH G64 highlights the challenges astronomers face in predicting which stars are about to explode as supernovae. Stars surrounded by dense, dusty material can appear cooler and redder than they truly are, potentially leading to misclassifications. Additionally, the complex circumstellar environment around WOH G64 could significantly affect the appearance of any future supernova explosion, depending on the viewing angle.

The details

Observations of WOH G64 over several decades show that the star underwent a dramatic transition around 2014. Prior to that, it exhibited the characteristics of a very cool, swollen red supergiant, with regular brightness variations likely caused by changes in the surrounding dust. However, between mid-2013 and mid-2014, the star became much bluer, indicating a significant increase in temperature, likely more than 1,000 Kelvin. Since then, the star's brightness has become irregular, including a sharp fade during 2025.

  • Around 2014, WOH G64 underwent a dramatic transition from a cool red supergiant to a warmer, short-lived phase.
  • In 2011, a strong dimming event hit the star.
  • Observations in 2025 suggest the star has returned to features consistent with a red supergiant.

The players

WOH G64

A giant red supergiant star located in the Large Magellanic Cloud, one of the most extreme known in its class.

Gonzalo Muñoz-Sanchez

The lead author of the study on WOH G64, affiliated with the National Observatory of Athens.

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What they’re saying

“This study highlights a practical problem astronomers face when they try to identify which stars are about to explode. A star buried in dusty circumstellar material can look cooler and redder than it truly is. That means some supernova progenitors may be misclassified if researchers rely mostly on color and brightness, without detailed spectra.”

— Gonzalo Muñoz-Sanchez, Lead author (Nature Astronomy)

What’s next

The study authors cannot predict the future of the WOH G64 system, as the basic physical and orbital details remain poorly understood. Further observations and analysis will be needed to determine if the star is indeed on the path to a supernova explosion.

The takeaway

The dramatic changes observed in the red supergiant star WOH G64 highlight the complex and unpredictable nature of the final stages of a massive star's life. This case underscores the challenges astronomers face in identifying potential supernova progenitors, as stars surrounded by dense material can appear very different from their true state.