Nebular abundances in southern symbiotic stars

Abstract

We have calculated relative elemental abundances for a sample of 43 symbiotic stars. Helium abundances and the relative elemental abundances N/O, Ne/O were derived from new spectra collected in the optical range through low dispersion spectroscopy and from IUE low resolution spectra (SWP camera). 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.