Stellar Growth Fueled by Gas “Highways,” New Research Reveals
For decades, astronomers believed that massive โคstars gained their size by accumulating material โfrom large, rotating disks โofโ dust adn gas.However, a recent study conducted by an international team, including researchers from Kyoto University and theโ University of Tokyo, challenges thisโค long-held assumption.
The research โฃsuggests that young stars are primarily โฃfedโ by “streamers” – substantial โฃflows ofโ gas extending from distances greater than 1,000 astronomical units,effectively acting as โvast conduits delivering material to the star. According to lead author โFernando Olguin, these streamers represent a new understanding of how stars build mass.
To โinvestigateโ thisโ hypothesis, โขthe team focused on observing โขstar-forming regions in greater detail than previously possible. Because high-mass stars form โคfurther away than their smaller counterparts, a powerful observatory was required. Thay utilized the Atacama Largeโ millimeter/submillimeter Array (ALMA) in Chile,โค aโค network ofโข antennas designed to detect faint millimeter-wavelength emissions from dust and molecules.
ALMA’s high precision allowed the team to โobserveโค a young star receiving material from โคtwo distinct streamers. One streamer exhibited aโค velocity pattern indicative of both rotationโ and inward movement, suggesting it’s โrapidly delivering a important amountโ of gas to the star’s core, overcoming the outward pressure generated by the โคstar itself.
Surprisingly, the researchers โขdid not find the expectedโค large dust disk, typically predicted to span hundreds of astronomical โunits. “We found streamers feeding what was thought to be aโข disk, โbut to our surprise, there is either no disk or it is indeed extremelyโ small,” โคOlguin explained.
This revelation indicates โthat streamers can efficiently transport large โฃquantities of gas to star-forming regions, even in the presence of stellar feedback, regardless of whether a disk is present around the central star.
The team intends to expand theirโ investigation by studying additional โstar-forming regions toโฃ determine if thisโ streamer-fed accretion process isโฃ a common mechanism for the formation of massive stars. They also plan to analyze the gas closer to the star to confirm or refute the existence of โsmaller disks.
This research,published on โAugust 20,2025,in Science Advances (DOI: โข10.1126/sciadv.adw4512),offers a new pathway to โฃunderstanding stellar growth and challenges existing models ofโข star formation.
