The Spectral Energy Distribution and the UV Excess in the Herbig be Candidate HD 45677

The newly recognized Herbig Be star, HD 45677 (B2, 7.5 ≤ V ≤ 8.7), traditionally classified as a B[e] star, has recently been found to have the signatures of a young energetic premain sequence (PMS) star, via UV spectropolarimetry, high-dispersion observations, and through the re-analysis of its infrared excess. Furthermore, low-dispersion IUE data have been used to detect significant UV excesses, which are model independent for fluxes between 2000–3000 A. The UV data also indicate a complex spectral type; the depth of the absorption lines suggest B1-B3 with a luminosity III-IV, whereas the unreddened continuum fluxes are better modeled by an O9-B0 star, making this object one of the earliest PMS star known. This multi-temperature spectral feature is a hallmark of objects seen edge-on, through an optically thick disk, undergoing episodes of mass accretion in their inner regions, such as the well-studied FU Ononis objects. In recent photometric data we have found short-term variability in all Stromgren indices; especially remarkable is ΔVy ~ 0.1 mag in a timescale of hours.