{"paper":{"title":"First Astronomical Detection of the Cumulene Carbon Chain Molecule H_2C_6 in TMC1","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"A. Kov\\'acs, C. A. Gottlieb, M. C. McCarthy, M. J. Travers, P. Thaddeus, R. peng, T. B. H. Kuiper, T. Velusamy, W. D. Langer","submitted_at":"1997-02-21T00:28:52Z","abstract_excerpt":"The cumulene carbenes are important components of hydrocarbon chemistry in low mass star forming cores. Here we report the first astronomical detection of the long chain cumulene carbene H_2C_6 in the interstellar cloud TMC1, from observations of two of its rotational transitions: $J_{K,K'} = 7_{1,7} \\rightarrow 6_{1,6}$ at 18.8 GHz and $8_{1,8} \\rightarrow 7_{1,7}$ at 21.5 GHz, using NASA's Deep Space Network 70 m antenna at Goldstone, California. In addition we also observed the shorter cumulene carbene, H_2C_4 at the same position. The fractional abundance of H_2C_6 relative to H_2 is about"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/9702183","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}