Tootfinder

Water Detection in the Interstellar Object 3I/ATLAS
Zexi Xing, Shawn Oset, John Noonan, Dennis Bodewits
https://arxiv.org/abs/2508.04675 https://arxiv.org/…

Water Detection in the Interstellar Object 3I/ATLAS
We report the first detection of water activity in the third confirmed interstellar object, 3I/ATLAS, based on ultraviolet imaging with the \emph{Neil Gehrels-Swift Observatory}. Observations acquired with the Ultraviolet/Optical Telescope on 2025 July 31st - Aug 1st revealed OH (A$^2Σ$ -- X$^2Π$) emission near 3085~Å. The water production rate results highly depend on the reddening assumption. For a reddening of 38.6\% between 5437.8~Å and 3325.7~Å, the water production rate is $(1.35 \pm…