Nebular abundances of southern symbiotic stars

Instituto de Astronomia, Geofisica e Ciências Atmosféricas (IAG), Universidade de São Paulo, São Paulo, Brazil e-mail: [gjmluna;roberto]@astro.iag.usp.br

Received: 10 September 2004
Accepted: 8 February 2005

Abstract

We have calculated relative element abundances for a sample of 43 symbiotic stars. Helium abundances and the relative elemental abundances N/O, Ne/O, Ar/O were derived from new spectra collected in the optical range through low dispersion spectroscopy. The He ionic abundances were derived taking into account self-absorption effects in Balmer lines. We found that the symbiotic stars in the galactic bulge have heavy element abundances showing the same wide distribution as other bulge objects. In the galactic disk, the symbiotic stars follow the abundance gradient as derived from different kinds of objects.