We have observed six relatively low energy transitions of HC9N in the circumstellar envelope of IRC + 10216. We find this long carbon-chain molecule to have a mean excitation temperature of Tex = 12 +/- 3 K which is similar to the values reported previously for HC3N and HC5N. If this cool HC9N gas extends to a radius of about 25 arcsec, we calculate a column density of N about 4.0 x 10 exp 13/sq cm. We also report detection of the N = 2-1 transition of C3N.
No takes yet. Share an insight, caveat, or question.
Bell et al. (1992) studied this question.