A&A Supplement series, Vol. 127, January II 1998, 243-249
Received February 26; accepted May 13, 1997
N.G.Beskrovnaya - M.A.Pogodin - R.V.Yudin - G.A.P.Franco - S.L.A. Vieira - A. Evans
Send offprint request: N.G.Beskrovnaya
Central Astronomical Observatory of the Russian Academy of Sciences at Pulkovo, 196140 Saint-Petersburg, Russia
Departamento de Fısica - ICEX - UFMG, Caixa Postal 702, 30.161-970 - Belo Horizonte - MG, Brazil
Department of Physics - Keele University, Keele, Staffordshire ST5 5BG, UK
We present new results of a spectroscopic and polarimetric investigation of the candidate young Herbig Ae/Be star HD163296. Twenty two spectra of this object near the , HeI 5876 and DNaI lines had been obtained in 1992-1995 at the Astrophysical National Laboratory of Brazil (LNA). In addition, forty seven high-resolution spectra in H and H were obtained at the ESO (Chile) in 1991-1992. -polarimetry (about forty measurements of the Stokes parameters in each passband) were carried out at the SAAO (South Africa) in July 17-30, 1995.
Striking profile variability has been found in all the lines on time scales from hours to months. Analysis of the profiles revealed manifestations of a remote cool shell which is in active interaction with the variable kinematically stratified stellar wind. Signs of cyclic positional variations of the H and H emission peaks were observed during five nights in July, 1991.
Sinusoidal variations of the linear polarization parameters detected in July, 1995 are explained in the framework of a model involving magnetized gaseous condensation, rotating in the envelope with the period of 15 days.
Marginal detection of circular polarization is also reported.
keywords: line: profiles -- polarization -- stars: circumstellar matter -- stars: individual (HD163296) -- stars: mass loss -- stars: pre-main sequence