Researchers using the James Webb Space Telescope have detected water and cosmic dust surviving just 0.55 light-years from Sagittarius A*, the supermassive black hole at the center of the Milky Way. According to a study published August 11 in Astronomy & Astrophysics, the discovery around an aging star known as IRS 3 demonstrates that molecular material can persist in extreme galactic environments previously thought too harsh for survival.
Detecting Water Near Sagittarius A*
The galactic center represents one of the most punishing environments in the universe, exposed to intense radiation and packed densely with stars. However, observations from the James Webb Space Telescope’s Mid-Infrared Instrument (MIRI) revealed clear evidence of water within the stellar envelope of IRS 3, according to findings detailed by the European Space Agency. Florian Peißker of the University of Cologne, lead author of the study, noted that dust production remains remarkably resilient even under these extreme conditions.
IRS 3 is classified as an asymptotic giant branch star. This stellar classification indicates that the object has reached a late stage of evolution, shedding vast quantities of gas and dust through powerful stellar winds. These dying stars function as cosmic recycling centers, returning material to space that eventually contributes to future generations of stars and planets. Macarena Garcia Marin, an ESA astronomer and co-author of the study, stated that detecting water confirms molecular material can endure environments dominated by intense radiation.
Reconstructing the Stellar Envelope of IRS 3
To understand how the star maintains its output, researchers combined spectroscopic observations of IRS 3 with computer simulations modeling how light travels through surrounding material. This approach allowed the team to map the structure of the star’s envelope. The analysis uncovered a layered, shell-like distribution of silicate dust stretching roughly 10,000 astronomical units from the star.
Temperatures across this vast envelope drop sharply. Near the surface of IRS 3, temperatures reach approximately 1,700 degrees Fahrenheit, or 927 degrees Celsius. In the outermost regions of the dust shell, temperatures plunge to minus 280 degrees Fahrenheit, equivalent to minus 173 degrees Celsius. While the Webb telescope observations do not quantify the total volume of water present, the confirmation of its existence proves that essential chemical ingredients for star and planet formation can withstand proximity to a supermassive black hole with a mass of roughly 4 million suns.
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