Emission bands obtained in the region 3900–4500 Å by a radio-frequency discharge in thiophene are studied; they are assigned to the HCCS transient species whose absorption spectrum was recently observed. A rotational analysis is carried out for the strong bands, which are assigned to a 2Πi–2Πi transition in which both states are close to Hund's case (a). Vibrational assignments are discussed.