CO observations of mass outflow from the infrared star CIT 6

Results are presented for observations of CO emission from the molecular envelope surrounding the carbon star CIT 6 (IRC + 30219) made at five epochs spanning 17 months. There is no evidence for any variation in the CO line intensity on this time scale, but the intensity is much lower than that reported by previous authors. In addition, an earlier report of (C-13)O line emission cannot be confirmed, and the carbon isotope ratio C-12/C-13 is measured to be greater than 20. The shape of the CO emission line observed at all epochs can be fitted by a uniformly expanding cloud model in which the CO is optically thin except through the longest lines of sight.