===== Detection of Ethynylcyclopropynylidyne, c-C3C2H, in the ISM =====

 C. Cabezas, M. Agúndez, R. Fuentetaja, Y. Endo, N. Marcelino, B. Tercero, J. R. Pardo, P. de Vicente, and J. Cernicharo\\
reported on the\\
**[[https://doi.org/10.1051/0004-6361/202244063|Discovery of the Cyclic C<sub>5</sub>H Radical in TMC-1]]**\\
//Astron Astrophys.// **663**, Art. No. L2 (2022).\\
Transitions with //J"// = 4 to 6 and //K<sub>a</sub>// = 1 between 33.0 and 46.4 GHz were detected in the course of a molecular line survey of the prototypical cold dark molecular cloud TMC-1 carried out with the Yebes 40 m radio telescope. Fine structure splitting was resolved throughout, hyperfine splitting in many cases. The rotational temperature was determined as 6.0 ± 0.5 K. The //c//-C<sub>5</sub>H to //l//-C<sub>5</sub>H ratio is about 0.07, very different from the //c//-C<sub>3</sub>H to //l//-C<sub>3</sub>H ratio of ~5.5.


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Contributor(s): H. S. P. Müller 07, 2022

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