Free Astronomy Magazine January-February 2024

JANUARY-FEBRUARY 2024 T his mosaic shows, at its centre, a real image of the young star system HH 1177, in the Large Magellanic Cloud, a galaxy neighboring the Milky Way. The image was obtained with the Multi Unit Spectroscopic Explorer (MUSE) on ESO’s Very Large Telescope (VLT) and shows jets being launched from the star. Re- searchers then used the Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner, to find evidence for a disc surrounding the young star. An artist’s impression of the system, showcasing both the jets and the disc, is shown on the right panel. [ESO/A. McLeod et al./M. Kornmesser] U sing ALMA, in which ESO is a partner, astronomers have for the first time found a disc around a young star outside our own galaxy. This video sum- marises the discovery. [ESO] an ambulance siren changes as it passes you and the frequency of the sound goes from higher to lower.” The detailed frequency measure- ments from ALMA allowed the au- thors to distinguish the characteristic spin of a disc, confirming the detec- tion of the first disc around an extra- galactic young star. Massive stars, like the one observed here, form much more quickly and live far shorter lives than low-mass stars like our Sun. In our galaxy, these massive stars are notoriously challenging to observe and are often obscured from view by the dusty ma- terial from which they form at the time a disc is shaping around them. However, in the Large Magellanic Cloud, a galaxy 160,000 light-years away, the material from which new stars are being born is fundamentally different from that in the Milky Way. Thanks to the lower dust content, HH 1177 is no longer cloaked in its natal cocoon, offering astronomers an unobstructed, if far away, view of star and planet formation. “We are in an era of rapid technological ad- vancement when it comes to astro- nomical facilities,” McLeod says. “Being able to study how stars form at such incredible distances and in a different galaxy is very exciting.” !