The observation of tricarbon (C3) in the circumstellar shell
IRC +10216 by was reported by
Hinkle et al. in 1988.
Unlike many identifications, which are made by matching features from the pure rotational
spectrum, the detection of C3 involved its coupled vibration-rotation spectrum.
Further sources where tricarbon has been seen include the protoplanetary nebula
IRAS 22272 + 5435 and
toward HD 210121.
It has also been detected by means of a pure vibrational line in Sgr B2 and IRC +10216
by Cernicharo et al.
was also one of the earliest species to be observed in comets, as reported
by Huggins in 1881. This
was evidentally forgotten for