The discovery of thioformyl cation (HCS+ or protonated carbon monosulfide)
was reported by Thaddeus, Guélin, & Linke in 1981
based on observations over several years in Orion A, the
DR 21 region in Cygnus, and Sgr B2 using various
telescopes, including the Bell Labs.
7 meter telescope in Crawford Hills.
Experimental detection of the observed J=1-2 transition was reported concurrently by
Gudeman et al., the group of
Claude Woods. What began as the detection of an apparent
triplet was recognized as three different interstellar species (also including
Three other lines assigned tentatively to HCS+ reported in the initial astronomical
detection were not definitely identified until
Bogey et al.
measured the microwave spectrum through the J=7-6 transition.