===== On the Detection of HOCS+ in the Interstellar Medium ===== M. Sanz-Novo, V. M. Rivilla, I. Jiménez-Serra, J. Martín-Pintado, L. Colzi, S. Zeng, A. Megías, Á. López-Gallifa, A. Martínez-Henares, S. Massalkhi, B. Tercero, P. de Vicente, D. San Andrés, S. Martín, and M. A. Requena-Torres\\ reported on the\\ **[[https://doi.org/10.3847/1538-4357/ad2c01|Interstellar Detection of O-protonated Carbonyl Sulfide, HOCS+]]**\\ //Astrophys. J.// **965**, Art. No. 149 (2024).\\ The cation was detected in the course of a molecular line survey of the Galactic Center molecular cloud G+0.693–0.027 employing the Yebes 40 m and IRAM 30 m radio telecopes. The transitions cover 34 to 161 GHz with //J"// = 2, 3, 6 − 13 and //Ka// = 0. These //Ka// = 0 are all considerably blended with //Ka// = 0 lines of HNC34S because their //B + C// values are nearly identical. The contribution of HNC34S could be accounted for accurately through lines of HNCS, OCS, and OC34S and turned out to be less than that of HOCS+. Several lines are slightly or more severely blended in addition, but this is in most cases also well accounted. The cation is about a factor of 400 less abundant than OCS, about a factor of 7 less abundant than the isoelectronic HNCS, about a factor of 31 less abundant than the isovalent HOCO+, but at least more than a factor of 2 more abundant than the lower energy isomer HCSO+, which was not detected.\\ \\ V. Lattanzi, M. Sanz-Novo, V. M. Rivilla, M. Araki, H. A. Bunn, J. Martín-Pintado, I. Jiménez-Serra, and P. Caselli\\ published more recently on\\ **[[https://doi.org/10.1051/0004-6361/202451518|Advancing Spectroscopic Understanding of HOCS+: Laboratory Investigations and Astronomical Implications]]**\\ //Astron. Astrophys.// **689**, Art. No. A260 (2024).\\ After detection of HOCS+ //a//-type transitions with //Ka// > 0, it was possible to identify //Ka// = 1 transitions in the line survey described above. Most of the transitions were heavily blended, but some were sufficiently clear. \\ ---- Contributor(s): H. S. P. Müller; 04, 2024; 09, 2024 ----