Saturday, September 27, 2025

NASA’s Webb Explores Largest Star-Forming Cloud in Milky Way

Stars, gas and cosmic dust in the Sagittarius B2 molecular cloud glow in near-infrared light, captured by Stars, gas and cosmic dust in the Sagittarius B2 molecular cloud glow in near-infrared light, captured by Webb’s NIRCam instrument. 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. 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)

Webb’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. 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)



NASA’s James Webb Space Telescope has revealed a colorful array of massive stars and glowing cosmic dust in the Sagittarius B2 molecular cloud, the most massive and active star-forming region in our Milky Way galaxy.

“Webb’s powerful infrared instruments 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.

The difference longer wavelengths of light make, even within the infrared 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. 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. Has it been going on for millions of years? Or has some unknown process triggered it only recently?

Astronomers hope Webb will shed light on why star formation in the galactic center is so disproportionately 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 showing us, there are also new mysteries to explore, and it’s exciting to be a part of that ongoing discovery.”

The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).




Related Information

Read more: NASA’s Webb Reveals New Features in Heart of Milky Way

Explore: ViewSpace interactive image tour of the center of the Milky Way

Explore: ViewSpace interactive views of the Eagle Nebula in different forms of light

Read more: Webb’s Star Formation Discoveries

Read more: Star formation in the Cat’s Paw Nebula

More Webb News

More Webb Images

Webb Science Themes

Webb Mission Page



Related For Kids

What is the Webb Telescope?

SpacePlace for Kids



En Español

Ciencia de la NASA

NASA en español

Space Place para niños