The search for short-lived cosmic events like supernovae wasn’t design mission of Webb telescope, but it could make a surprise sometimes. In the telescope’s recent images, astronomers found a galaxy that appeared bright and dimmed slightly over five days — typical supernova behavior, likely the first since Webb became operational.
The galaxy is named SDSS.J141930.11+5251593 and is 3 to 4 billion light-years away from us. In the past, the Hubble Telescope did not find this bright object when observing this galaxy, because the real death of a star is less than 1 second. The explosions caused by death quickly brighten for a few days, then fade away over the next few months.
Supernova explosions are just a blink of an eye for the universe, so the search is often left to ground-based telescopes that image the vast sky nightly; Webb telescope in the other hand, despite its wide range of uses, was not designed to look for supernova transients, but it actually could. It was quite lucky to find a supernova shortly after its brightness peaked.
While we need more data to further confirm the supernova, the information we have so far does match the supernova.
The team has not yet decided whether to continue the inspection. Although it is the first supernova discovered by the Webb telescope, as far as the supernova itself is concerned, it has no particular need for follow-up observations.
If astronomers finally decide to investigate further, they can observe how the light from the supernova dims over time to determine what type of supernova it is;
In addition, measuring supernova spectra can also reveal the chemical composition of the parent star, and thus understand why the star exploded so violently.