Massive Star WOH G64 May Soon Explode Into a Supernova

The red supergiant star WOH G64, located in the Large Magellanic Cloud, has undergone a significant change in brightness and color, prompting astronomers to conclude it may be on the verge of a supernova explosion.

Observations from multiple observatories, including the European Southern Observatory’s Very Large Telescope and NASA’s Neil Gehrels Swift Observatory, show that WOH G64 has dimmed in visible light while increasing in infrared emissions over the past decade. This shift suggests the star has ejected a substantial amount of dust and gas, forming a thick circumstellar envelope that obscures its visible output but re-radiates energy at longer wavelengths.

WOH G64 is one of the largest known stars, with a radius approximately 1,540 times that of the Sun. If placed at the center of our solar system, its surface would extend beyond the orbit of Jupiter. Such massive stars burn through their nuclear fuel rapidly and end their lives in core-collapse supernovae, which can outshine entire galaxies for a brief period.

According to Dr. Gerd Weigelt, an astronomer at the Max Planck Institute for Radio Astronomy who has studied WOH G64 for over two decades, the recent changes align with theoretical models of stars in the final stages before explosion. “We are seeing the star lose mass at an increased rate, and the dust shell around it is growing denser,” Dr. Weigelt explained in a 2024 interview with the European Southern Observatory. “Here’s consistent with what we expect when a red supergiant is preparing to go supernova.”