Overview
- On Tuesday, August 11, 2026, an international team reported that JWST’s MIRI data from 2025 reveal clear silicate signatures and the first robust detection of water in the envelope of IRS 3.
- IRS 3 sits about 0.55 light‑years from Sagittarius A* and the team’s radiative-transfer models reconstruct a layered, shell-like dust envelope roughly 10,000 astronomical units across with temperatures falling from about 1200 K near the star to about 100 K at the edge.
- The mid-infrared spectra identify IRS 3 as an oxygen-rich asymptotic giant branch star, overturning earlier suggestions that the source was carbon-rich.
- Researchers estimate IRS 3 has roughly six times the Sun’s mass, is about 72 million years old, and is in a phase of intense mass loss that is steadily expanding its dusty, molecule-bearing envelope.
- Because AGB stars shed heavy elements and molecules as they die, the finding that dust and water survive so close to a supermassive black hole implies these stars can directly help enrich the galactic centre and future observations with instruments such as ELT/METIS will probe the models and chemistry in more detail.