Webb Telescope Identifies Progenitor Star of Supernova 2025pht

Astronomers have utilized the James Webb Space Telescope (JWST) to identify the progenitor of supernova 2025pht, marking the first time JWST has been used for such a discovery. The supernova, detected on June 29, 2025, in the galaxy NGC 1637, originated from a red supergiant star previously obscured by a dense shell of dust.

By aligning pre-explosion images from both the Hubble Space Telescope and JWST, researchers pinpointed the exact star that exploded. The star's unusually red appearance indicated significant dust surrounding it, which had blocked shorter, bluer wavelengths of light. This finding supports the hypothesis that many massive stars are enshrouded in dust, making them difficult to detect before they explode.

Lead author Charlie Kilpatrick of Northwestern University stated, :

"We've been waiting for this to happen – for a supernova to explode in a galaxy that Webb had already observed. We combined Hubble and Webb data sets to completely characterize this star for the first time."

Co-author Aswin Suresh added, :

"It's the reddest, most dusty red supergiant that we've seen explode as a supernova."

The study also revealed that the dust surrounding the star was carbon-rich, a surprising finding since red supergiants are typically associated with silicate-rich dust. This suggests that carbon may have been dredged up from the star's interior shortly before the explosion. The research provides new insights into the late stages of massive star evolution and the role of dust in obscuring these stars from detection.