This flow of gas sends material from the surrounding cloud of the Perseus star forming region directly into the newborn binary star system called SVS 13A.
Stars are born from clouds of gas and dust, but recent observations suggest that star birth is much more dynamic than previously thought.
New data from the Atacama Large Millimeter/submillimeter Array (ALMA) has captured both dust and molecules swirling around the SVS 13A system, revealing that magnetic fields don't just pass through these stellar nurseries—they actively control the flow of material, providing a preferred route for gas to the disk where new stars and planets form.
“Imagine a garden hose, but instead of water, it gently delivers star-building material along a winding path carved by unseen forces,” said Dr. Paulo Cortes, an astronomer at the NSF National Radio Astronomy Observatory and the Joint ALMA Observatory.
“This is the picture that emerges from the ALMA observations: a channel of gas, called a sub-Alfvénic streamer, regulated by spiral magnetic field lines.”
“These new data give us a new window into star formation.”
“This streamer shows how magnetic fields can regulate star formation, shaping a stream of material like a dedicated highway that cars can drive on.”
ALMA images and data show two spiral arms of dust surrounding the stars, with a flow of gas following the same path.
This remarkable alignment suggests that the gas in the streamer is moving slowly compared to what was previously thought, supporting the idea of a magnetized channel rather than a turbulently collapsing cloud.
The fact that such a streamer exists and connects the cloud to the disk, feeding material in a controlled manner, means that gravity and magnetism play a crucial role in building stars and forming the planets that may eventually form around them.
This groundbreaking result marks the first time astronomers have directly mapped both a streamer and its driven magnetic field in a single observation.
“The subalvén streamer suggests a new role for the magnetic field when gravity dominates, where it acts as a 'conductor' to facilitate the fall of material from the shell onto the disk,” the astronomers said.
conclusions will appear this week in Letters in an astrophysical journal.
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PC Cortez etc.. 2025. First results of ALPPS: sub-Alfvenic streamer in SVS 13A. ApJL 992, L31; doi: 10.3847/2041-8213/ae0c04
