Thousands of never-before-seen newborn stars have been discovered in 30 Doradus, a stellar nursery photographed by the NASA/ESA/CSA James Webb Space Telescope. The Tarantula Nebula, so named because of the appearance of its dusty filaments in previous telescopic photographs, has long been a favorite of astronomers researching star formation. Webb discovers distant background galaxies as well as the intricate structure and composition of the nebula's gas and dust.
The Tarantula Nebula is the biggest and brightest star-forming area in the Local Group of galaxies, which is just 161,000 light-years away in the Large Magellanic Cloud galaxy. It is regarded to be the home of the hottest, most enormous stars. Three of Webb's high-resolution infrared sensors were directed towards the Tarantula. When seen using Webb's Near-Infrared Camera (NIRCam), the region resembles a burrowing tarantula's silk-lined lair. The NIRCam picture's hole has been hollowed down by blistering radiation from a cluster of huge new stars, which glitter pale blue in the image. Only the densest regions of the nebula's surroundings withstand erosion by the intense stellar winds of these stars, generating pillars that appear to point back toward the cluster. These pillars house growing protostars, which will ultimately emerge from their dusty cocoons and contribute to the formation of the nebula.
One extremely young star was spotted doing precisely that by Webb's Near-Infrared Spectrograph (NIRSpec). Previously, astronomers suspected that this star was older and in the process of cleaning out a bubble around itself. However, NIRSpec revealed that the star was only just emerging from its pillar and was still surrounded by an insulating cloud of dust. This event of star formation-in-action could not have been revealed without Webb's high-resolution spectra at infrared wavelengths.
When observed in the longer infrared wavelengths detected by Webb's Mid-infrared Instrument, the area takes on a distinct look (MIRI). Cooler gas and dust sparkle as the blazing stars vanish. Points of light within the stellar nursery clouds suggest embedded protostars that are still accumulating mass. While lesser wavelengths of light are absorbed or deflected by dust grains in the nebula and so never reach Webb, longer mid-infrared wavelengths pierce that dust, exposing a hitherto unexplored cosmic environment.
One of the reasons astronomers are interested in the Tarantula Nebula is that it has a comparable chemical makeup to the massive star-forming areas found at the universe's "cosmic noon," when the universe was just a few billion years old and star creation was at its height. Our Milky Way galaxy's star-forming regions do not produce stars at the same pace as the Tarantula Nebula and have a distinct chemical makeup. As a result, the Tarantula is the closest (i.e., most detailed) illustration of what was going on in the cosmos as it reached its bright high noon. Webb will allow scientists to compare and contrast views of star formation in the Tarantula Nebula with deep studies of distant galaxies from the age of cosmic midday.
Despite thousands of years of stargazing, the star formation process continues to be riddled with mysteries, many of which stem from our inability to obtain clear photographs of what was going on beneath the dense clouds of stellar nurseries. Webb has already begun to disclose a previously unseen cosmos, and he is only getting started on rewriting the stellar origin myth.
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