Dust and water spotted close to giant black hole
Astronomers using the James Webb Space Telescope have detected dust and water forming near the Milky Way’s central supermassive black hole, challenging assumptions about extreme environments.
Observations with the NASA/ESA/CSA James Webb Space Telescope reveal that dust and water can form and persist close to Sagittarius A*, the supermassive black hole at the Milky Way’s center. The evolved star IRS 3, located just 0.55 light-years away, continues to shed material despite intense radiation, providing new insights into stellar processes in extreme environments. The findings suggest that even near a black hole, stars can contribute to the cosmic material cycle essential for future star and planet formation.
The study, led by Florian Peißker of the University of Cologne, used Webb’s MIRI instrument to analyze IRS 3’s infrared light, identifying oxygen-rich silicate dust and water in its envelope. Previously thought to be carbon-rich, the star’s chemical composition was reassessed, revealing a layered dust shell extending up to 10,000 astronomical units with temperatures ranging from 1200 Kelvin near the star to 100 Kelvin at its outer edge.
Researchers estimate IRS 3 has a mass six times that of the Sun and is approximately 72 million years old, losing material at a significant rate. The detection of water, a first for this star, indicates molecular material can survive near a supermassive black hole, suggesting evolved stars may play a key role in enriching galactic centers with dust and gas.
The observations, part of the MICONIC Guaranteed Time Observations programme, were conducted in 2025 using Webb’s MIRI instrument. The results challenge prior assumptions about the harsh conditions near black holes, demonstrating that dust production and stellar evolution can persist even in such extreme regions.