A remarkable new study using NASA’s James Webb Space Telescope has uncovered shocking details about a star-forming region known as Sagittarius C—a turbulent area located near the Milky Way’s center. Published in The Astrophysical Journal, this study offers unprecedented views into one of the most active zones in our galaxy. The findings reveal long, glowing filaments, energetic protostars, and powerful magnetic fields that are reshaping the way stars are born and die.
Sagittarius C: The Galactic Hotspot for Star Formation
Sagittarius C is one of the densest, most dynamic regions in the Milky Way, filled with gas, dust, and energetic processes. “It’s in a part of the galaxy with the highest density of stars and massive, dense clouds of hydrogen, helium, and organic molecules,” says John Bally, professor of astrophysical and planetary sciences at CU Boulder. “It’s one of the closest regions we know of that has extreme conditions similar to those in the young universe.”
This makes Sagittarius C a star-forming machine—but with an unexpected twist. Despite its density, fewer stars are forming here than scientists had anticipated. The Webb Telescope’s detailed images could finally provide the answers to this long-standing puzzle.
The Surprising Role of Magnetic Fields in Star Formation
One of the most eye-catching discoveries in Sagittarius C is the presence of powerful magnetic fields threading through the region. These magnetic forces create filaments of hot gas, and scientists now believe they are slowing down the star formation process. “Because of these magnetic fields, Sagittarius C has a fundamentally different shape, a different look than any other star-forming region in the galaxy away from the galactic center,” says Samuel Crowe, a co-author of the study.
These magnetic fields, stretching through the dense clouds of gas, might be acting as a barrier that prevents the gas from collapsing into new stars as quickly as it would in other regions. This phenomenon helps explain the puzzle of why the region isn’t forming stars at the expected rate.
The Unexpected Discovery of Long Filaments
Perhaps the most surprising find was the filaments of plasma scattered across Sagittarius C. These bright, elongated structures were completely unexpected. “We were definitely not expecting those filaments,” says Rubén Fedriani, co-author of the study and postdoctoral researcher at the Instituto de Astrofísica de Andalucía. “It was a completely serendipitous discovery.”
The filaments, some stretching several light-years, are formed by plasma—hot, charged gas that glows brightly in the presence of intense magnetic fields. This discovery not only challenges current models of star formation but also provides crucial data for understanding how stars evolve in extreme environments.
How Stars Form and Fade in Extreme Conditions
The birth of stars in molecular clouds is an eventful and violent process. As gas clouds collapse under gravity, new stars emerge, emitting intense radiation that eventually blows away the surrounding material. “Even the sun, we think, formed in a massive cluster like this,” explains John Bally. “Over billions of years, all of our sibling stars have drifted away.”
In Sagittarius C, this same process is unfolding, but the powerful radiation from young stars is already stripping away the gas and dust that once formed them. The result? A star-forming region that could soon lose its ability to create new stars.
