{"id":226729,"date":"2025-12-09T01:21:03","date_gmt":"2025-12-09T07:21:03","guid":{"rendered":"https:\/\/lifeboat.com\/blog\/2025\/12\/ch_3oh-and-hcn-in-interstellar-comet-3i-atlas-mapped-with-the-alma-atacama-compact-array"},"modified":"2025-12-09T01:21:03","modified_gmt":"2025-12-09T07:21:03","slug":"ch_3oh-and-hcn-in-interstellar-comet-3i-atlas-mapped-with-the-alma-atacama-compact-array","status":"publish","type":"post","link":"https:\/\/lifeboat.com\/blog\/2025\/12\/ch_3oh-and-hcn-in-interstellar-comet-3i-atlas-mapped-with-the-alma-atacama-compact-array","title":{"rendered":"CH$_3$OH and HCN in Interstellar Comet 3I\/ATLAS Mapped with the ALMA Atacama Compact Array"},"content":{"rendered":"<p>CH_3OH and HCN in Interstellar Comet 3I\/ATLAS Mapped with the ALMA Atacama Compact Array: Distinct Outgassing Behaviors and a Remarkably High CH_3OH\/HCN Production Rate Ratio.<\/p>\n<hr>\n<p>We report the detection of methanol (CH$_3$OH) toward interstellar comet 3I\/ATLAS using the Atacama Compact Array of the Atacama Large Millimeter\/Submillimeter Array (ALMA) on UT 2025 August 28, September 18 and 22, and October 1, and of hydrogen cyanide (HCN) on September 12 and 15. These observations spanned pre-perihelion heliocentric distances ($r_H$) of 2.6 \u2014 1.7 au. The molecules showed outgassing patterns distinct from one another, with HCN production being depleted in the sunward hemisphere of the coma, whereas CH$_3$OH was enhanced in that direction. Statistical analysis of molecular scale lengths in 3I\/ATLAS indicated that CH$_3$OH included production from coma sources at $L_p258$ km at 99% confidence, although low signal-to-noise on long baselines prevented definitively ruling out CH$_3$OH as purely a parent species.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>CH_3OH and HCN in Interstellar Comet 3I\/ATLAS Mapped with the ALMA Atacama Compact Array: Distinct Outgassing Behaviors and a Remarkably High CH_3OH\/HCN Production Rate Ratio. We report the detection of methanol (CH$_3$OH) toward interstellar comet 3I\/ATLAS using the Atacama Compact Array of the Atacama Large Millimeter\/Submillimeter Array (ALMA) on UT 2025 August 28, September 18 [\u2026]<\/p>\n","protected":false},"author":427,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[],"class_list":["post-226729","post","type-post","status-publish","format-standard","hentry","category-space"],"_links":{"self":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/226729","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/users\/427"}],"replies":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/comments?post=226729"}],"version-history":[{"count":0,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/226729\/revisions"}],"wp:attachment":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/media?parent=226729"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/categories?post=226729"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/tags?post=226729"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}