C3S AND C5S IN IRC+10216

In this Letter we report the detection of the J = 4-3 transition of C3 S in the envelope of IRC + 10216. When this result is combined with pr eviously published data at higher frequencies, it is apparent that the re are at least two rotational temperature regimes for this molecule i n the circumstellar envelope. We also report a tentative detection of the J = 13-12 transition of C5S in the envelope of IRC + 10216. Assumi ng the observed feature is due to C5S, we find that N(C5S)/N(C3S) almo st-equal-to 0.5.