HCN and CN in Comet 2P/Encke: Models of the non-isotropic, rotation-modulated coma and CN parent life time

► We present models that retrieve the dependence of cometary gas flux on direction. ► We determine the rotation rate of Comet 2P/Encke from observations of its CN coma. ► We determine the sense of rotation of Comet 2P/Encke from HCN spectra. ► We find evidence in Comet 2P/Encke for gas flow across its terminator. ► Comet 2P/Encke's outgassing before perihelion is likely to come from deeper layers.