On the nature of the Herbig Be star V 380 Orionis

We discuss new and archive spectroscopic and photometric observations of th e Herbig Ae star V 380 Ori obtained between 1978 and 1995 and covering at d ifferent epochs the wavelength range from 1200 Angstrom to 5 mu m. The coor dinated JHKLM and CVF infrared observations and optical spectroscopy made a t ESO of March 1985 confirm the presence of a strong IR excess due to emiss ion from hot cicumstellar dust. The comparison with IR photometry from the literature suggests the presence of oscillations, without secular variation s. The optical spectrum of V 380 Ori, observed at ESO during 1983-1985, and at OHP in January 1995, remained substatially stable, and was all the time characterized by a large number of broad (FWHM similar to 150 km s(-1)) pe rmitted emission lines, probably formed an a rotating optically thick disk. The strongest Fe II lines have complex profile with a principle central em ission and a blue-shifted (-140 km s(-1)) wind component, the redward compo nent probably being occulted by the disk. The multiplet 42 lines have P Cyg ni absorption components shifted by -250 km s(-1) which should be associate d with a teneous cool wind. We remark the secular behavior of the stellar a ctivity probe He I 5876 Angstrom line, which is present in all our spectra as a broad emission, while in other times it was absent or in absorption. T he ultraviolet (IUE) spectrum shows a short wavelength cut off at 1300 Angs trom typical of a B9-A0 star, with a rich absorption spectrum, which is tho ught to be produced ina an optically thick stellar envelope or wind. The 21 75 Angstrom interstellar band strength is consistent with a mean galatic-ty pe extinction law with an EB-V= 0.20 +/- 0.05, much smaller than that deriv ed from the visual (similar to 0.5), which suggests an anomalous local UV e xtinction. The comparison of the archive IUE data shows that during 1978-19 89 there was no significant flux variations, with the possible exception of the UV Mg II emission line.