A&A Supplement series, Vol. 129, May I 1998, 479-488
Received April 24; accepted October 16, 1997
N.A. Tomov 
- M.T. Tomova
- D.V. Raikova 
Send offprint request: N.A. Tomov
National Astronomical Observatory Rozhen,
P.O. Box 136, BG-4700 Smolyan, Bulgaria
e-mail: rozhen@tu-plovdiv.bg
Institute of Astronomy, Blvd. Tzarigradsko shosse 72,
BG-1784 Sofia, Bulgaria
Intermediate resolution observations of the blue spectrum of the symbiotic star AG Peg, being at a colliding wind stage in its evolution with decreasing luminosity and mass-loss rate of its hot component, have been realized. Profiles, fluxes and radial velocity data have been obtained. They are compared with earlier data, taken approximately at the same orbital phases. It turns out that the radial velocities of many lines differ from these data which is probably determined by a change of dynamics of the nebula. The comparison shows, also, the intensity of all emission lines has decreased, but the velocity of the wind of the hot component is invariable. The fluxes of the lines appearing in this wind have been theoretically calculated by means of values of the mass-loss rate obtained on the basis of contemporaneous UV observations. They are in good agreement with the observed fluxes which is a confirmation of this mass-loss rate. The intensity decrease of the narrow emission lines is discussed.
keywords: binaries: symbiotic -- stars: individual: AG Peg -- stars: mass-loss -- line: profiles