The detection of a circumstellar feature was tentatively attributed to the J = 1 – 0 transition of PH₃ by two groups almost simultaneously:
E. D. Tenenbaum and L. M. Ziurys,
A Search for Phosphine in Circumstellar Envelopes: PH₃ in IRC +10216 and CRL 2688 ?
Astrophys. J. 680, L121–L124 (2008).
M. Agúndez, J. Cernicharo, J. R. Pardo, M. Guélin, T. G. Phillips,
Tentative Detection of Phosphine in IRC +10216
Astron. Astrophys. 485, L33–L36 (2008).
The first work ascribed a feature at v_LSR of the star to PH₃ close to the star. The second paper, however, convincingly assigned that feature to SiS in its v = 4 excited vibrational state. In the first work, the feature was not only detected in the envelope of the carbon-rich AGB star IRC +10216, but also in the protoplanetary nebula CRL 2688. The feature was also searched for in the protoplanetary nebula CRL 618, but was found to be overlapped by a line of HC₃N in its v₇ = 4 excited vibrational state.

M. Agúndez, J. Cernicharo, L. Decin, P. Encrenaz, and D. Teyssier,
reported recently on the
Confirmation of Circumstellar Phosphine
Astrophys. J. 790, Art. No. L27 (2014).
The essentially overlapping J = 2 – 1, K = 0 and 1 transitions were observed in emission near 533.8 GHz with the Herschel/HIFI instrument toward the famous carbon-rich AGB star CW Leonis, also known as IRC +10216.

Contributor(s): H. S. P. Müller; 06, 2008; 07, 2014