The optical spectrum of HR 4049 (includes a line identification from 3650 to 10850ang)

Abstract

High-resolution optical spectra (UES/WHT) of the extreme metal-poor post-AGB star HR4049 were obtained at four different orbital phases. The spectra cover the wavelength region from 3650ang to 10850ang at a resolution of R=5.2x10^4. These observations are supplemented with four high-resolution spectra of the NaI D1 & D2 and CaII K lines at R=10^5 (CAT/CES). The optical spectrum shows 217 spectral lines: the Balmer series (H alpha - H35), the Paschen series (P9 - P23), NI, OI and numerous CI lines. We show that the lines of H alpha, H beta, H gamma and NaI D show significant changes in profile between different observation dates. Nine components were identified in the profile of the NaI D lines of which three are circumstellar and six interstellar. The stronger CI lines are asymmetric and we derive a post-AGB mass-loss of Mdot= 6x10^-7Msol/yr from the asymmetry. The [OI] 6300ang line has been detected in emission at the system velocity and we argue that the emission is from an almost edge-on disk with a radius of about 20 Rstar.