===== Isocyanobutadiyne, HC4NC, in the Interstellar Medium =====

C. Xue, E. Willis, R. Loomis, K. Lee, A. Burkhardt, C. Shingledecker, S. Charnley, M. Cordiner, S. Kalenskii, M. McCarthy, E. Herbst, A. Remijan, and B. McGuire\\
reported on the\\
**[[https://doi.org/10.3847/2041-8213/aba631|Detection of Interstellar HC<sub>4</sub>NC and an Investigation of Isocyanopolyyne Chemistry under TMC-1 Conditions]]**\\
//Astrophys. J. Lett.// **900**, Art. No. L9 (2020).\\
The observations were obtained in the course of the line survey GOTHAM (Green Bank Telescope Observations of TMC-1: Hunting for Aromatic Molecules). The data were recorded with very high resolution which resolves, at least in part, the complex velocity structure and the <sup>14</sup>N hyperfine structure splitting of the //J// = 8 → 7, 9 → 9, and 10 → 9 transitions near 22.4, 25.2, and 28.0 GHz, respectively, at the expense of noise levels of about the same level as the individual lines. The analysis was improved by employing a stacking technique. The HC<sub>4</sub>NC to HC<sub>4</sub>CN ratio is about 1 to 200, while the HC<sub>2</sub>NC to HC<sub>2</sub>CN ratio is about 1 to 50.\\

Almost at the same time,\\
J. Cernicharo, N. Marcelino, M. Agúndez, C. Bermúdez, C. Cabezas, B. Tercero, and J. R. Pardo\\
reported on the\\
**[[https://doi.org/10.1051/0004-6361/202039274|Discovery of HC<sub>4</sub>NC in TMC-1: A study of the isomers of HC<sub>3</sub>N, HC<sub>5</sub>N, and HC<sub>7</sub>N]]**\\
//Astron. Astrophys.// **642**, Art. No. L8 (2020).\\
The observations were obtained with the Yebes 40m radio telescope in the course of a line survey covering 31.0–50.3 GHz and cover //J"// = 11 to 15 of the molecule. The findings are compatible with the ones mentioned above.


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Contributor(s): H. S. P. Müller; 10, 2020

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