Free Astronomy Magazine September-October 2023

26 SEPTEMBER-OCTOBER 2023 ASTRO PUBLISHING Revealing the hidden seeds of giant stars by ALMA Observatory Nicolás Lira U sing the Atacama Large Mil- limeter/submillimeter Array (ALMA), an international re- search team led by Kaho Morii, Patricio Sanhueza, and Fumitaka Nakamura has made a pioneering discovery, unveiling over 800 “stellar seeds” nestled within massive cos- mic clouds. These insights are mon- umental in decoding the enigmatic process of high-mass star formation, an essential cog in generating life’s building blocks. ALMA’s state-of-the- art sensitivity and resolution proved pivotal in shedding light on this mys- tery. The researchers used ALMA to peer into 39 massive cosmic clouds, known as Infrared Dark Clouds (IRDCs), believed to be the nurseries of high-mass stars. With ALMA’s capabilities, over 800 stellar seeds, or molecular cloud cores, were identified within these clouds, making it the most extensive sample ever discovered. Astound- ingly, 99% of these seeds lack the mass typically thought necessary to grow into high-mass stars. This groundbreaking observation indi- cates that high-mass stars might fol- low a different growth trajectory than smaller stars. Moreover, it was observed that core density, rather than mass, may be the critical factor in high-mass star formation. Kaho Morii, a graduate student at the University of Tokyo, shared, “We have shown with more certainty als. It seems that the environment of dense material is more important than the original mass for massive stars formation.” Patricio Sanhueza of the National Astronomical Observatory of Japan than previous studies that high-mass stars have a different growth sce- nario from low-mass stars. Also, we can infer that denser cores in clus- ters may grow up more efficiently by accumulating surrounding materi-