JWST Finds Water and Dust Surviving Just Half a Light-Year From the Milky Way's Supermassive Black Hole

Envelope composition: The star is surrounded by a layered, shell-like envelope extending roughly 10,000 astronomical units from the star . The envelope contains oxygen-rich dust, including silicates (identified by the 9.7 µm Si-O stretching feature and the 18.5 µm O-Si-O bending mode) and alumina . Crucially, the team also detected water molecules in the envelope for the first time .

How MIRI settled the chemical debate: Previous observations had left ambiguity about whether IRS 3 was carbon-rich or oxygen-rich . Webb's Mid-Infrared Instrument (MIRI) obtained the first continuous mid-infrared spectrum of the star, revealing clear signatures of silicate dust and conclusively identifying IRS 3 as an oxygen-rich (O-rich) AGB star . This ruled out a carbon-dominated composition .

Why the water detection is significant

The presence of water molecules is especially surprising because the region around Sagittarius A* is dominated by intense ultraviolet and X-ray radiation from the black hole and surrounding hot gas, which would normally destroy fragile molecules like water very quickly . "Galactic centers are among the most extreme environments, so understanding whether stars can continue enriching their surroundings there is an important question," said Florian Peißker, an astronomer at Germany's University of Cologne, who led the study . The survival of water in this environment demonstrates that molecular material can persist even under extreme radiative conditions .

Implications for star and planet formation near galactic centers

These findings suggest that evolved stars near galactic centers can continue to enrich their surroundings with dust and water—key ingredients for planet formation and the chemistry of life—even in environments previously thought to be too hostile for such processes . This indicates that material recycling and the potential for planet formation may be possible much closer to a supermassive black hole than previously believed . The discovery essentially shows that the building blocks of future stars and planets can form even under extreme gravitational stress and intense radiation .