AN INNER GASEOUS DISK AROUND THE HERBIG Be STAR MWC 147

We present high spectral resolution, optical spectra of the Herbig Be star MWC 147, in which we spectrally resolve several emission lines, including the [O I] lines at 6300 and 6363 angstrom. Their highly symmetric, double-peaked line profiles indicate that the emission originates in a rotating circumstellar disk. We deconvolve the Doppler-broadened [O I] emission lines to obtain a measure of emission as a function of distance from the central star. The resulting radial surface brightness profiles are in agreement with a disk structure consisting of a flat, inner, gaseous disk and a flared, outer, dust disk. The transition between these components at 2-3 AU corresponds to the estimated dust sublimation radius. The width of the double-peaked Mg II line at 4481 angstrom suggests that the inner disk extends to at least 0.10 AU, close to the corotation radius.