The dicarbon phosphide (CCP) radical was detected in IRC +10216 by Halfen, Cloutier, and Ziurys in 2008. Five doublet pairs of lines were identified using the 12 m telescope at the Arizona Radio Observatory on Kitt Peak. A detailed study of the rotatational specta of CCP, including ¹³C isotopomers followed in 2009.

CCP is a cousin of CCN, which has not yet been observed. Guélin and Cernicharo were unable to detect it the early 1990s. Another search in IRC +10216 15 years by Fuchs et al. also found no evidence of CCN.