Free Astronomy Magazine July-August 2026

29 JULY-AUGUST 2026 ASTRO PUBLISHING lution of the small- scale structure of star-forming regions even in nearby gal- axies, opening a new window for studying the earliest stages of star for- mation beyond the Milky Way. To achieve this re- sult, the research team pushed ALMA to the limits of its capabilities for this type of study, reach- ing an angular reso- lution of 0.05 arc- seconds—equivalent to distinguishing a one-euro coin from 100 kilometers away. This precision al- lowed them to re- solve structures as small as 2,000 astro- nomical units, iden- tifying 70 dense cores embedded within four protoclusters at a dis- tance of 160,000 light-years. To confirm the nature of these struc- tures and exclude contamination from ionized gas—a particular chal- lenge in such active regions—the team combined ALMA observations with data from the Hubble Space Telescope and the James Webb Space Telescope, which also con- firmed that the detected cores are still in an early phase of their evolu- tion. “We are truly excited about the results achieved with this study. Thanks to ALMA, studying core masses in our Galaxy is becoming al- most ‘routine,’ suggesting in partic- ular that the mass of our cores seems to evolve, especially in high-mass re- gions,” says Alessio Traficante, lead author of the study. “Until now, no one had attempted to push this type of research into extra-galactic re- gions, which require significantly T he star-forming region 30 Doradus, better known as the Tarantula Nebula, is imaged here in great detail by Webb’s Near-Infrared Camera. The horizontal edge of this image spans about 340 light-years. [NASA, ESA, CSA, STScI, Webb ERO Production Team] higher resolution and sensitivity than studies conducted within the Milky Way. The identification of more than 70 cores in 30 Dor-10 was by no means guaranteed, consider- ing we were observing an environ- ment with an interstellar medium whose characteristics are profoundly different from those found in the main massive star-forming regions of our Galaxy. We had no idea what to expect before seeing the highly detailed images obtained by ALMA.” By comparing the mass distribution of these cores with those observed in the Milky Way, the researchers found that both follow a similar trend consistent with Salpeter’s Law—a notable result given the markedly different conditions in the Large Magellanic Cloud, including lower metallicity, different turbu- lence regimes, and a more strongly ionized interstellar medium. Crucially, while the initial mass func- tion of stars in such extreme environ- ments can show an excess of massive stars, the earliest phase of core for- mation appears to follow the same patterns seen in our Galaxy, suggest- ing that these young cores continue to accrete mass over time regardless of their surroundings. The findings suggest that the initial fragmentation of molecular clouds —the process that leads to the for- mation of dense cores— may be largely independent of the sur- rounding galactic environment. This work, connected to ALMA Large Programs such as ALMA-IMF and AL- MAGAL, opens the door to a system- atic study of star formation in other galaxies using techniques previously applied only within the Milky Way, and allows astronomers to begin testing whether the physical laws governing the birth of stars hold constant across the universe. !