Sagittarius B2 Molecular Cloud

The Mid-Infrared Instrument (MIRI) on NASA’s James Webb Space Telescope captured glowing cosmic dust heated by very young massive stars in unprecedented detail in this image of the Sagittarius B2 (Sgr B2) molecular cloud released on Sept. 24, 2025.

Sgr B2 is the most massive, and active star-forming region in our galaxy, located only a few hundred light years from our central supermassive black hole. While Sgr B2 has only 10% of the galactic center’s gas, it produces 50% of its stars. Astronomers want to figure out why it is so much more active than the rest of the galactic center.

MIRI has both a camera and a spectrograph that sees light in the mid-infrared region of the electromagnetic spectrum. MIRI’s view reveals colorful stars punctuated occasionally by bright clouds of gas and dust. Further research into these stars will reveal details of their masses and ages, which will help astronomers better understand the process of star formation in this dense, active galactic center region.

Image credit: Image: NASA, ESA, CSA, STScI, Adam Ginsburg (University of Florida), Nazar Budaiev (University of Florida), Taehwa Yoo (University of Florida); Image Processing: Alyssa Pagan (STScI)