At a mere 161,000 light-years away in the Large Magellanic Cloud, the Tarantula Nebula is the largest and brightest star-forming region in the Local Group, as scientists comfortingly call the galaxies nearest our Milky Way. The cloud is home to the hottest, most massive stars known. James Webb has sent back some great snaps.
The Tarantula gets its name from earlier images in which clouds of gas and stars appeared as dusty filaments resembling the legs of a hairy spider. The crisp results arriving from the Webb telescope's three high-resolution infrared devices make the name outdated, but the detailed information revealed will more than compensate the scientific community.
The Tarantula is officially known as 30 Doradus.
Doradus is interesting to astronomers chiefly because the nebula has a similar type of chemical composition to the gigantic star-forming regions observed from a time when the cosmos was only a few billion years old and star formation was at its peak.
Star-forming regions in our Milky Way galaxy are not producing stars at the same furious rate as the Tarantula Nebula, and have a different chemical composition.
This makes the Tarantula the closest, and easiest to see, example of what was happening in the universe as it reached its most brilliant phase, called "high noon" by astronomers.
Webb will provide space scientists the opportunity to compare and contrast observations of star formation in the Tarantula Nebula with the telescope’s deep observations of distant galaxies from the actual era of that far off cosmic mid-day.
Cutting through the stellar gloom
For the technically minded, the image above is actually a composite of information captured by three different cameras.
The telescope's primary imager, the Near-Infrared device, found the cavity in the center of the nebula had been hollowed out by radiation carried on stellar winds emanating from a cluster of massive young stars, which appear as pale blue dots.
Webb's Near-Infrared Spectrograph analyzes light patterns to determine the composition of the objects seen,
Finally, the Mid-infrared Instrument uses longer wavelengths of infrared to pierce through dust clouds that absorb or scatter shorter wavelengths.
The visual impact is to make the hot stars fade, allowing the cooler regions to be seen more clearly, revealing never-before-seen points of light within the stellar nursery. Each point is a still-growing protostar.
The area covered by the image at the top of the article is 340 light years from edge to edge, in other words, the disance light can travel in 340 years, at the rate of 300 million metres every second.
