Ce n’était pas prévu, mais le James Webb a repéré sa première supernova

Ce n'était pas prévu, mais le James Webb a repéré sa première supernova

An unexpected “photobomb” that could well offer new subjects of study to the star of the telescopes.

Astronomers recently made an intriguing discovery while reviewing a series of new shots produced by the James Webb Space Telescope; they saw a surprisingly bright object in a part of the sky where the venerable Hubble had not yet seen anything. And if the researchers’ predictions are correct, it could be a supernova; that would be a small event in itself, since the JWST was not designed to observe them.

In any case, this is the opinion of Mike Engesser, an American astronomer from the Space Telescope Science Institute interviewed by Inverse; he seems relatively certain of the facts about him, even if he willingly admits that a small part of uncertainty remains. ” We would need more time and data, but what we have is for a supernova anyway, so it’s a very good candidate. “, he says.

Supernovae, objects difficult to study

If this observation excites the team so much, it’s because these events are particularly difficult to catch on the spot. There are different types, but very commonly, supernovae are cataclysmic phenomena that accompany the end of a star’s life.

They are associated with flashes of light of phenomenal intensity that can make it possible to locate them…provided you look in the right place at the right time. And as soon as you include those factors in the equation, everything becomes much more complicated.

An image of the same portion of the sky taken by Hubble. The famous supernova is indistinguishable here. © STScI reverse pathway

Telescope observing time is short, so astronomers can’t afford to stare at an old star all the time in the hope that it will break up; to observe them, you have to cross your fingers that an event of this type “photobombs” another observation.

However, the sudden increase in brightness only lasts a few days; after this time, the latter gradually decreases over a few months, making the observations less and less interesting; The optimal viewing window is therefore ridiculously narrow, knowing that a star can easily live for several tens of millions of years.

And there’s one more thing that the researchers say should have made this observation particularly unlikely in Webb’s case. Remember that it tracks extremely distant objects; after all, the purpose of it is to trace the origins of our universe. By definition, it scans a very small portion of the vault of heaven. This corresponds to the surface of the sky that would be hidden from you if you held a grain of sand at arm’s length!

The JWST, future supernova hunter?

It’s easy to understand why the researchers didn’t expect to eliminate supernovae there. But this observation changes the situation; According to Engesser, if the JWST was able to capture this event, there’s no reason you can’t find it in plenty of other shots! ” We might have a very good chance of detecting supernovae all the time “, he rejoices.

In any case, it would be an advance as substantial as it was unexpected; today there are cohorts of astronomers who spend most of their time chasing these phenomena, and one can imagine that they are already rubbing their hands.

These phenomena are full of clues about the life cycle of stars and their role in the global dynamics of the cosmos; Researchers even hope that the oldest supernovae ever observed will contain interesting information about the early universe and the first generations of stars.

If the JWST locates them, it will certainly be a great resource for specialists. The JWST definitely never stops pushing the limits of astronomy!

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