Free Astronomy Magazine November-December 2025

39 ASTRO PUBLISHING of Webb’s images of Sagittarius B2 are the portions that remain dark. These ironically empty-looking areas of space are actually so dense with gas and dust that even Webb cannot see through them. These thick clouds are the raw material of future stars and a cocoon for those still too young to shine. The high resolution and mid-infrared sensitivity of Webb’s MIRI (Mid-In- frared Instrument) revealed this re- gion in unprecedented detail, includ- ing glowing cosmic dust heated by very young massive stars. The red- dest area on the right half of MIRI’s image, known as Sagittarius B2 North, is one of the most molecularly rich regions known, but astronomers have never seen it with such clarity. (Note: North is to the right in these Webb images.) The difference longer wavelengths of light make, even within the in- frared spectrum, are stark when comparing the images from Webb’s MIRI and NIRCam (Near-Infrared Camera) instruments. Glowing gas and dust appear dramatically in mid- infrared light, while all but the brightest stars disappear from view. In contrast to MIRI, colorful stars steal the show in Webb’s NIRCam image, punctuated occasionally by bright clouds of gas and dust. Fur- ther research into these stars will re- veal details of their masses and ages, which will help astronomers better understand the process of star for- mation in this dense, active galactic center region. Has it been going on for millions of years? Or has some un- known process triggered it only re- cently? Astronomers hope Webb will shed light on why star formation in the galactic center is so dispropor- tionately low. Though the region is stocked with plenty of gaseous raw material, on the whole it is not nearly as productive as Sagittarius B2. While Sagittarius B2 has only 10 percent of the galactic center’s gas, it produces 50 percent of its stars. “Humans have been studying the stars for thousands of years, and there is still a lot to understand,” said Nazar Budaiev, a graduate student at the University of Florida and the co- principal investigator of the study. “For everything new Webb is show- ing us, there are also new mysteries to explore, and it’s exciting to be a part of that ongoing discovery.” W ebb’s MIRI instrument shows the Sagittarius B2 region in mid-infrared light, with warm dust glowing brightly. Only the brightest stars emit strongly enough to appear through the dense clouds as blue pinpoints. [NASA, ESA, CSA, STScI, Adam Ginsburg (University of Florida), Nazar Budaiev (University of Florida), Taehwa Yoo (University of Florida); Image Processing: Alyssa Pagan (STScI)] !