The $^{\bf\beta}$ Pictoris phenomenon among Herbig Ae/Be stars. UV and optical high dispersion spectra

Abstract

We present a survey of high dispersion UV and optical spectra of Herbig Ae/Be (HAeBe) and related stars. We nd accreting, circumstellar gas over the velocity range +100 to +400 km s 1 , and absorption proles similar to those seen toward Pic, in 36% of the 33 HAeBe stars with IUE data as well as in 3 non-emission B stars. We also nd evidence of accretion in 7 HAeBe stars with optical data only. Line prole variability appears ubiquitous. As a group, the stars with accreting gas signatures have higher v sini than the stars with outflowing material, and tend to exhibit large amplitude ( 1 m ) optical light variations. All of the program stars with polarimetric variations that are anti-correlated with the optical light, previously interpreted as the signature of a dust disk viewed close to equator-on, also show spectral signatures of accreting gas. These data imply that accretion activity in HAeBe stars is preferentially observed when the line of sight transits the circumstellar dust disk. Our data imply that the spectroscopic signatures of accreting circumstellar material seen in Pic are not unique to that object, but instead are consistent with interpretation of Pic as a comparatively young A star with its associated circumstellar disk.