Astronomy and Astrophysics Supplement Series, Vol. 120, November II 1996, 157-177
C.A. Grady , M.R. Pérez , A. Talavera , K.S. Bjorkman ,
D. de Winter , P.-S. Thé , F.J. Molster
, M.E. van den Ancker ,
M.L. Sitko , N.D. Morrison , M.L. Beaver
, B. McCollum and
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Eureka Scientific, 2452 Delmer Street, Suite 100,
Oakland CA 94602, U.S.A.
Applied Research Corp., Suite 1120, 8201 Corporate Dr., Landover, MD 20785, U.S.A.
Laboratorio de Astrofisica Espacial y Fisica Fundamental, I.N.T.A., Apartado 50727, 28080- Madrid, Spain
Space Astronomy Laboratory, University of Wisconsin, Madison WI 53706-1390, U.S.A.
Astronomical Institute ``Anton Pannekoek'', University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands
Department of Physics, University of Cincinnati, Cincinnati OH 45221-0011, U.S.A.
Ritter Observatory and Department of Physics and Astronomy, University of Toledo, Toledo OH 43606, U.S.A.
Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, U.S.A.
CSC-IUE Observatory, GSFC, Greenbelt, MD 20771, U.S.A.
Department of Physics, East Tennessee State University, Box 70652, Johnson City TN 37614, U.S.A.
Received August 30, 1995; accepted April 10, 1996
Abstract:We present a survey of high dispersion UV and optical spectra of Herbig Ae/Be (HAeBe) and related stars. We find accreting, circumstellar gas over the velocity range +100 to +400 km s, and absorption profiles 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 find evidence of accretion in 7 HAeBe stars with optical data only. Line profile variability appears ubiquitous. As a group, the stars with accreting gas signatures have higher than the stars with outflowing material, and tend to exhibit large amplitude () 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.
Key words: stars: Pic: pre-main sequence --- circumstellar matter --- line: profiles --- ultraviolet: stars