Astronomers have directly imaged a twisted magnetic field around a newborn star's outflow for the first time, confirming a theory that has puzzled astrophysicists for decades. The team used the Atacama Large Millimeter/submillimeter Array (ALMA), a partnership involving the U.S. National Science Foundation's National Radio Astronomy Observatory, to capture high-resolution images showing how magnetic fields wrap tightly around jets of gas ejected from forming stars.
Young stars launch powerful jets of material into space at supersonic speeds. Scientists have long debated the mechanism driving these jets. The leading theoretical model proposed that magnetic fields, twisted and wound around the star's equator, could channel and accelerate the outflowing gas. However, direct observation of this twisted field structure remained elusive until now.
The ALMA observations reveal the magnetic field configuration predicted by decades of theoretical work. The tightly wrapped magnetic geometry acts like a cosmic channel, confining the gas and accelerating it into narrow, collimated jets. This mechanism explains why jets from young stars remain so focused and powerful over vast distances rather than dissipating quickly into space.
The research resolves a fundamental question in star formation. When stars first coalesce from collapsing clouds of gas and dust, they spin rapidly and develop powerful magnetic fields. Understanding how these fields organize the ejected material illuminates the physics governing early stellar evolution. The jets themselves play crucial roles in star formation, removing excess angular momentum that would otherwise prevent the star from contracting further.
ALMA's unprecedented sensitivity and resolution in millimeter and submillimeter wavelengths made this observation possible. By detecting polarized radiation from dust grains aligned with the magnetic field, the team could map the three-dimensional structure of the field around the jet. This technique opened a new observational window into magnetic field structures that were previously invisible.
The findings validate magnetic field-