In recent images of a galaxy called SDSS.J141930.11+5251593, captured by the James Webb Space Telescope, astronomers spotted something unusual: an extremely bright object. This unusual happening might be a supernova, suspect astronomers.

Webb observed the galaxy twice. The bright object dimmed over five days, suggesting it could have been a supernova.

For one thing, the object is extremely bright compared to the rest of the galaxy. If it is a supernova, it is probably the first supernova spotted by the Webb Telescope.

Astronomer Mike Engesser of the Space Telescope Science Institute (STScI) tells Inverse, “We would need more time series data to make a determination, but the data we do have does match that of a supernova, so it’s a very good candidate.”

Galaxy SDSS.J141930.11+5251593 is located 3 to 4 billion light-years from Earth.

Engesser said, “Primarily, it’s exciting because we have shown that we’re able to find and detect new transients with Webb, which was something that JWST is not designed to do. But it’s one of the things we’re showing we’re able to do in sort of an ad hoc way.”

The discovery is surprising as the James Webb Space Telescope wasn’t built to search for supernovas. This work is often done by large-scale survey telescopes that scan vast portions of the sky at short intervals. Webb, on the other hand, looks in great detail into a very small area of the universe.

Engesser and his colleague compared new data from Webb’s NIRCam instrument to Hubble images of the same area. A software was used to spot any differences that might reveal ‘transients’ objects that appear, vanish, brighten, or dim on a timescale we can see in real-time. That’s how the team found the supernova.