| C. Cabezas, K. Vávra, G. Molpeceres, L. Kolesniková, M. Agúndez, G. Vylitová, N. Marcelino, L. Hrubčík, R. Fuentetaja, T. Uhlíková, B. Tercero, J. Koucký, G. Esplugues, P. Kania, P. de Vicente, Š. Urban, and J. Cernicharo\\ | C. Cabezas, K. Vávra, G. Molpeceres, L. Kolesniková, M. Agúndez, G. Vylitová, N. Marcelino, L. Hrubčík, R. Fuentetaja, T. Uhlíková, B. Tercero, J. Koucký, G. Esplugues, P. Kania, P. de Vicente, Š. Urban, and J. Cernicharo\\ |
| Propenethial, also known as thioacrolein, was identified through four //a//-type transitions with //J// = 3 − 2 and 4 − 3 and //K<sub>a</sub>// ≤ 1 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 between 31.0 and 50.4 GHz. The transitions displayed resolved methyl internal rotation splitting; the E component of 3<sub>03</sub> − 2<sub>02</sub> is blended. A value of //T//<sub>rot</sub> = 9 K was assumed. Its column density is about a factor of 36 lower than that of acetaldehyde.\\ | Propenethial, also known as thioacrolein, was identified through //a//-type transitions with //J// = 6 − 5 to 9 − 8 and //K<sub>a</sub>// ≤ 1 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 between 31.0 and 50.4 GHz. Nine of the covered transitions were not or not severely blended; the signal-to-noise ratio was rather low for two of them. A value of //T//<sub>rot</sub> = 9 K was assumed. Its column density is about a factor of 27 and 7 lower than those of cyanothioformaldehyde andthioacetaldehyde, respectively. And it is only about a factor of 5 lower than that of propenal.\\ |