James Webb Telescope Detects Water and Cosmic Dust Near Star IRS 3, Close to Sagittarius A*

The James Webb Space Telescope has identified the presence of water and cosmic dust around the star IRS 3, located 0.55 light-years from Sagittarius A*, the supermassive black hole at the center of the Milky Way. This finding is notable because the region is exposed to intense radiation and hosts a high concentration of stars.

The detection was made using the MIRI instrument. For astronomy specialists, this demonstrates that molecules and dust particles are capable of persisting in one of the galaxy's most severe environments, according to a study.

Sagittarius A* has an estimated mass of about four million suns. The star IRS 3 is situated within this turbulent context and represents one of the brightest sources in the galactic core's infrared spectrum. This star is in an advanced stage of its evolution, characterized as an asymptotic giant branch star, which expels large volumes of gas and dust through vigorous stellar winds.

Understanding whether stars can continue enriching their surroundings is a crucial question, given that galactic centers constitute among the most extreme known environments. Researchers examined the spectrum of IRS 3 and conducted simulations to analyze how starlight interacts with the surrounding material. The work revealed a silicate dust structure organized in layers, extending over approximately ten thousand astronomical units.

The temperature varies significantly along this stellar envelope. Water was registered on this star for the first time, although the exact amount present was not determined by the observations. This result is particularly relevant because the strong radiation from the galactic center could theoretically prevent the survival of molecules, but IRS 3 indicates that this does not necessarily happen.

More information about the study

Macarena Garcia Marin, a co-author of the study and an astronomer at the European Space Agency, commented that the discovery of water is very encouraging, as it proves that molecular material can survive in an environment dominated by intense radiation.

Water and dust play important roles in the chemistry associated with star and planet formation. The material expelled by IRS 3 has the potential to integrate new generations of these celestial bodies at some point. The observation suggests that older stars can still release material into space even when very close to a supermassive black hole, helping to explain how molecules and dust are recycled in galactic cores.

In addition to locating water in an unexpected place, Webb captured a phase of this matter cycle in one of the most adverse regions of the Milky Way.