The James Webb Space Telescope is making it possible to detect more celestial objects we previously wouldn't be able to, including ones that can further our knowledge on how our universe began. A team of astronomers, for instance, detected a "rich population of brown dwarf candidates" outside our own galaxy for the first time. The image above was captured using the telescope's Near-InfraRed Camera (NIRCam) instrument.
We already know of the roughly 3,000 brown dwarfs inside the Milky Way, but Webb made it possible to find candidates 200,000 light years away from our planet. "Only with the incredible sensitivity and spatial resolution in the correct wavelength regime is it possible to detect these objects at such great distances," said Peter Zeidler, the team leader from AURA/STScI for the European Space Agency. "This has never been possible before and also will remain impossible from the ground for the foreseeable future."
Brown dwarfs are neither planets nor stars. They're free-floating objects around 13 to 75 times larger than Jupiter, and they aren't gravitationally bound to a star like exoplanets are. Yes, they're bigger than the biggest gas giants, but they're also not big enough to produce massive amounts of light, which is why they're sometimes called "failed stars." According to the scientists in this study, their observations support the theory that brown dwarfs form like stars do, they merely "don’t accrete enough mass to become a fully fledged star." As NASA notes, scientists think it's possible that a "great deal" of the universe's mass comes in the form of brown dwarfs. Seeing as they're mostly dark and can barely generate any light, they could help answer the "missing mass" problem that astronomers are still trying to solve.
The team found the new brown dwarf candidates in a star cluster called NGC 602 near the outskirts of the Small Magellanic Cloud dwarf galaxy. They explained that older Hubble observations showed that the cluster contains very young low mass stars, but Webb made it possible to look at them more closely. Based on what they've seen, the cluster exists in an environment comparable to the early universe, which means studying the brown dwarfs could provide more clues on how stars and planets formed billions of years ago.
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