===== Detection of Methyloxomethylium, CH3CO+, in the ISM ===== J. Cernicharo, C. Cabezas, S. Bailleux, L. Margulès, R. Motiyenko, L. Zou, Y. Endo, C. Bermúdez, M. Agúndez, N. Marcelino, B. Lefloch, B. Tercero, and P. de Vicente\\ reported on the\\ **[[https://doi.org/10.1051/0004-6361/202040076|Discovery of the acetyl cation, CH3CO+, in space and in the laboratory]]**\\ //Astron Astrophys.// **646**, Art. No. L7 (2021).\\ Eight transitions with //J'// = 2, 4, 5, and 6 and with //K// = 0 and 1 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 and the IRAM 30 m radio telescopes. The molecule was also identified in the cold dense cores L483, L1527, and L1544. ---- Contributor(s): H. S. P. Müller 02, 2021 ----