Hypothèse de Régénération Continue d'une Coque en Nickel sur 3I/ATLAS : Analyse Technique d'une Option Possible
2025/08/25 by Martin A. Cordiner, Martin Cordiner, Cordiner, Martin A. +25 · 9 voices · 23 citations
Physics and Astronomy · #Astrophysics and Star Formation Studies #Astronomy and Astrophysical Research #Astro and Planetary Science
paper · pdf · doi:10.48550/arxiv.2508.18209
Abstract
3I/ATLAS is the third confirmed interstellar object to visit our Solar System, and only the second to display a clear coma. Infrared spectroscopy with the James Webb Space Telescope (JWST) provides the opportunity to measure its coma composition and determine the primary activity drivers. We report the first results from our JWST NIRSpec campaign for 3I/ATLAS, at an inbound heliocentric distance of rH=3.32 au. The spectral images (spanning 0.6-5.3 μm) reveal a CO2 dominated coma, with enhanced outgassing in the sunward direction, and the presence of H2O, CO, OCS, water ice and dust. The coma CO2/H2O mixing ratio of 7.6±0.3 is among the highest ever observed in a comet, and is 4.5-sigma above the trend as a function of heliocentric distance for long-period and Jupiter-family comets (excluding the outlier C/2016 R2). Our observations are compatible with an intrinsically CO2-rich nucleus, which may indicate that 3I/ATLAS contains ices exposed to higher levels of radiation than Solar System comets, or that it formed close to the CO2 ice line in its parent protoplanetary disk. A low coma H2O gas abundance may also be implied, for example, due to inhibited heat penetration into the nucleus, which could suppress the H2O sublimation rate relative to CO2 and CO.
Citations
Cited by
Discussions
- Today our team released findings on the nature of the interstellar object 3I/ATLAS, based on our first round of JWST observations. The data are incredible: Not only did we detect and map gas and dust [bsky, 118 points, 5 comments]
- Lovely new 3I/ATLAS interstellar comet ☄️ observations identifying the volatiles in its coma, from the mighty JWST today: very rich in carbon dioxide! @drcordiner.bsky.social et al, ApJL submitted 🔭 [bsky, 66 points, 0 comments]
- Interstellar comet 3I/ATLAS is slowly giving up its secrets. New JWST observations give a great view of its lopsided, dusty coma & show unusually high levels of carbon dioxide billowing off its nucleu [bsky, 62 points, 3 comments]
- Alright, we know for sure it's a comet, can we now send Avi Loeb home until the next interstellar object is found? [bsky, 26 points, 3 comments]
- preprint is now out on arXiv arxiv.org/abs/2508.18209 [bsky, 7 points, 0 comments]
- JWST detection of CO2 dominated gas coma surrounding interstellar obj. 3I/ATLAS [hn, 3 points, 0 comments]
- +++ BREAKING +++ Alien metabolism produces CO₂. [bsky, 2 points, 0 comments]
- Today on the #arXiv : Cordiner et al. 2025, "JWST detection of a carbon dioxide dominated gas coma surrounding interstellar object #3I/ATLAS" - arxiv.org/abs/2508.18209 The comet has a lot of CO2, alo [bsky, 1 points, 0 comments]
- Today on the # arXiv : Cordiner et al. 2025, "JWST detection of a carbon dioxide dominated gas coma surrounding interstellar object # 3I /ATLAS " - https:// arxiv.org/abs/2508.18209 The comet has a lo [mastodon, 0 points, 0 comments]
Related