Free Astronomy Magazine November-December 2025

Webb explores largest star-forming cloud in the Milky Way by NASA/ESA/CSA Laura Betz, Leah Ramsay, Christine Pulliam N ASA’s James Webb Space Tele- scope has revealed a colorful array of massive stars and glowing cosmic dust in the Sagittar- ius B2 molecular cloud, the most massive and active star-forming re- gion in our Milky Way galaxy. “Webb’s powerful infrared instru- ments provide detail we’ve never been able to see before, which will help us to understand some of the still-elusive mysteries of massive star formation and why Sagittarius B2 is so much more active than the rest of the galactic center,” said astronomer Adam Ginsburg of the University of Florida, principal investigator of the program. Sagittarius B2 is located only a few hundred light-years from the supermassive black hole at the heart of the galaxy called Sagittarius A bove: Stars, gas and cosmic dust in the Sagittarius B2 molecular cloud glow in near-infrared light, captured by Webb’s NIRCam instru- ment. The darkest areas of the image are not empty space but are areas where stars are still forming inside dense clouds that block their light. [NASA, ESA, CSA, STScI, Adam Gins- burg (University of Florida), Nazar Bu- daiev (University of Florida), Taehwa Yoo (University of Florida); Image Processing: Alyssa Pagan (STScI)] A*, a region densely packed with stars, star-forming clouds, and com- plex magnetic fields. The infrared light that Webb detects is able to pass through some of the area’s thick clouds to reveal young stars and the warm dust surrounding them. How- ever, one of the most notable aspects