Discovery of the elusive thioketenylium, HCCS+, in TMC-1 C. Cabezas, M. Agúndez, N. Marcelino, B. Tercero, Y. Endo, R. Fuentetaja, J. R. Pardo, P. de Vicente and J. Cernicharo A&A, 657 (2022) L4 Published online: 07 January 2022 DOI: 10.1051/0004-6361/202142815