Hα orbital variations of the symbiotic star EG And from optical spectroscopy

In this contribution, we explore the orbital variability of the H alpha-line emission and absorption components of the symbiotic system EG And. We have found that the equivalent width of the core emission is the largest at the orbital phase phi approximate to 0.4 and the smallest at phi approximate to 0.2. This probably reflects an asymmetric distribution of the cool giant wind at the orbital-plane area. Furthermore, the core emission equivalent width has a secondary maximum at phi approximate to 0.1. The strongest absorption in the profile is measured around the inferior conjunction of the white dwarf, phi approximate to 0.4. This suggests that the ionized region is partially optically thick in the H alpha line.