Strong magnetic fields may hinder star birth, finds NASA’s Webb Telescope

An image of the Milky Way captured by the MeerKAT (formerly the Karoo Array Telescope) radio telescope array puts the James Webb Space Telescope’s image of the Sagittarius C region in context. (Image: NASA)

For decades, the center of our galaxy has held mysteries. Now, thanks to a stunning image and fresh research, scientists are finally seeing what lies behind the thick dust. The James Webb Space Telescope is offering new views into how stars form—or don’t—near the Milky Way’s core.

An image taken in 2023 of the Sagittarius C region has revealed surprising details. Scientists say they spotted outflows from young stars and patterns shaped by magnetic fields. These findings help explain why so few stars form in such a dense part of space.

“We’ve long wondered why this region is quiet,” said John Bally, astrophysicist at the University of Colorado Boulder. “There’s lots of gas and dust, but few stars.”

Bally is one of the study’s lead researchers. He said Webb’s infrared tools let scientists see through the clouds like never before. Previous tools like ALMA and Spitzer hinted at star formation, but Webb gave the clearest look yet.

In Sagittarius C’s brightest area, two giant stars are being born. Each is already over 20 times heavier than our Sun. Alongside older data from Spitzer, SOFIA, and Herschel, Webb helped confirm these details.

Spotting smaller stars is harder. They stay wrapped in dust, hidden from most tools. But by matching Webb’s images with ALMA data, researchers found five likely low-mass star candidates.

Scientists also identified 88 regions filled with shocked hydrogen gas. These areas form when jets from baby stars smash into surrounding gas. Among these signs, they found a new cloud with at least two more forming stars.

“This is the first time we’ve seen these outflows in infrared,” said Samuel Crowe, a co-lead of the study. “There’s still so much to learn about how stars form in this part of space.”

One of Webb’s most eye-catching finds was a series of long filaments. These run through hot hydrogen plasma around Sagittarius C. Bally’s team believes these shapes are formed by magnetic fields.

They think the motion of gas near the Milky Way’s giant black hole may twist and stretch the fields. These fields may stop gas from spreading or collapsing to form stars.

“We believe these magnetic forces are stronger than we thought,” Bally said. “They may be holding back star formation in this region.”

The same forces may explain why dense clouds in the Central Molecular Zone don’t produce more stars, despite their conditions.

Crowe added that magnetic fields could be key across other galaxies, too. “This is a topic that deserves much more attention,” he said.

The James Webb Space Telescope continues to unlock space’s hidden layers. It’s a joint effort by NASA, the European Space Agency, and the Canadian Space Agency.

With each new image, Webb brings us closer to answering cosmic questions – including how stars, planets, and galaxies form and change.