Free Astronomy Magazine November-December 2026

NOVEMBER-DECEMBER 2026 ASTRO PUBLISHING volved star, which is nearing the end of its life and shedding material into space. “This discovery was possible because of Webb’s highly capable in- frared instruments,” said Macarena Garcia Marin of ESA, a co-author of the study and PI of the MICONIC pro- gramme. “This is the first time a con- tinuous mid-infrared spectrum has been collected for this star, allowing us to detect the features from the sil- icate dust and uncover the star’s true chemical identity.” By combining Webb’s observations of the star’s spectrum with simula- tions of how its radiated light would move through different models of the surrounding enve- lope, the team were able to recon- struct the structure of the star’s envelope. Their results indicate a layered, shell-like distribution of dust extending roughly 10,000 as- tronomical units from the star, with temperatures falling from approxi- mately 1,200 kelvin close to the star to around 100 kelvin in the outer re- gions. The observations also re- vealed evidence for water within the envelope of IRS 3: the first clear detection of its kind for this object. “The detection of water is especially exciting because it shows that mo- lecular material can survive in an en- vironment dominated by intense radiation,” said Garcia Marin. “This tells us that even close to a super- massive black hole, stars can con- tinue contributing material back into their surroundings.” From the observations and stellar T his collage showcases the loca- tion of the highly evolved star IRS 3, which is located just 0.55 light- years from Sagittarius A*, the Milky Way galaxy’s central supermassive black hole. The images show a pro- gressinvely closer view of the region using ground- and space-based data. [ESA/Webb, NASA & CSA, NOIRLab/ NSF/AURA/E. Slawik/M. Zamani, ESO/S. Guisard, NASA/JPL-Caltech/ S. Stolovy (Spitzer Science Center/ Caltech), F. Peißker, J. Lu] modelling, the researchers estimate that IRS 3 has a mass of approxi- mately six times that of the Sun and is around 72 million years old. The star appears to be undergoing in- tense mass loss, ejecting material into space and creating the ex- tended envelope seen by Webb. These results suggest that evolved stars may continue playing an im- portant role in supplying dust to galactic centres — regions that were previously thought to be especially hostile to these processes. !