===== Detection of Ethynylthioxomethylium, HC3S+, in the ISM ===== J. Cernicharo, C. Cabezas, Y. Endo, N. Marcelino, M. Agúndez, B. Tercero, J. D. Gallego, and P. de Vicente\\ reported on the\\ **[[https://doi.org/10.1051/0004-6361/202040013|Space and laboratory discovery of HC₃S⁺]]**\\ //Astron Astrophys.// **646**, Art. No. L3 (2021).\\ The //J"// = 5 to 8 transitions between 32.8 and 49.2 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. The identity was confirmed through laboratory measurements. The C₃S to HC₃S⁺ ratio is 65 ± 20, and the HC₃O⁺ to HC₃S⁺ ratio is 1.0 ± 0.5. The C₃O to C₃S ratio, in contrast, is ~0.11. ---- Contributor(s): H. S. P. Müller 02, 2021 ----