Dust and water spotted close to giant black hole
ESA · 2026-08-11
Astronomers utilizing the James Webb Space Telescope have made unprecedented observations of IRS 3, a highly evolved star situated merely 0.55 light-years from Sagittarius A*, the Milky Way's central supermassive black hole. The star, nearing the end of its life in the asymptotic giant branch phase, is shedding gas and dust into space through powerful stellar winds. Lead author Florian Peißker of the University of Cologne highlighted the significance, stating that these findings confirm dust production remains resilient even in the extreme environments of galactic centers.
Co-author Macarena Garcia Marin of ESA noted that Webb's highly capable infrared instruments enabled the first continuous mid-infrared spectrum of IRS 3, revealing features of silicate dust and the star's chemical identity. By combining Webb's observations with simulations, researchers reconstructed the star's envelope, finding a layered, shell-like dust distribution extending approximately 10 000 astronomical units, with temperatures ranging from 1200 Kelvin near the star to 100 Kelvin in outer regions. Crucially, the observations also yielded the first clear detection of water within IRS 3's envelope, demonstrating molecular material can survive intense radiation near a supermassive black hole. Estimated to be around 72 million years old with a mass approximately six times that of the Sun, IRS 3 is undergoing intense mass loss. These results, obtained in 2025 as part of the MICONIC programme, suggest evolved stars continue to supply dust to galactic centers, previously considered hostile to such processes.
*The full article also explores the specific instrumentation used and the broader implications for understanding star evolution in extreme cosmic environments.*