The Herbig Be/Ae Star MWC 1080 and Its Associated Molecular Cloud. II. Optical Spectroscopic Observations

Molecular lines and optical observations have been carried out for the Herbig Be/Ae star MWC 1080, its nearby nebulosity, and the surrounding molecular cloud. In this paper the results of optical spectroscopic observations are presented. Long-slit spectra with dispersions of 237 and 116 Angstroms mm(-1) have been obtained. The spectra of MWC 1080 were used to classify the spectral type as being early A with a luminosity class of Ib--II. The Balmer-series lines show prominent P Cygni profiles up to Hepsilon . From these profiles, the mass-loss rate due to the stellar wind is roughly estimated to be 10(-6) MO yr(-1) ; the maximum velocity of the wind reaches up to 1000 km s(-1) . This stellar wind may be responsible for the mechanism that drives the molecular outflow and forms the cavity in the molecular disk. Nebular spectra show no evidence of shock or UV excitation, indicating a pure reflective origin of the nebula.