1995A&A...299..464H

We present observations of the unique pre-main sequence object LkHα 349, the central star of the cometary nebula IC1396A. The optical spectrum is dominated by strong P Cygni Balmer and NaD lines and the broad and shallow absorption lines of a rapidly rotating F8 star. The blue-shifted P Cygni absorption wings extend to 500-700km/s and are indicative of a very strong stellar wind. The spectral energy distribution from the optical through the far-infrared is that of a single F star with moderate extinction, a radius of 8.4R_☉ (L=84L_☉), and no obvious contribution from a circumstellar disk. The deconvolved absorption line broadening function shows a vsin i of 193±12km/s, suggesting that LkHα 349 is rotating at near break-up. LkHα 349 sits in the middle of a substantial circumstellar "hole" which it may have blown out of IC1396A. All of these characteristics can be understood if LkHα 349 is a pre-main sequence star of intermediate mass (γ3xM_☉) on its way towards becoming a Herbig Be star. The wind must be the star's response to the problem of rotating so quickly while rapidly contracting down to the main sequence. Due to the very short contraction times expected for intermediate-mass stars, LkHα 349 gives us a rare glimpse of a young star during a very short but important period in its pre-main sequence life.