DeGaPe 35: Amateur discovery of a new southern symbiotic star

In this work, we present the discovery and characterization of a new southern S-type symbiotic star, DeGaPe 35. We have obtained the low-resolution spectroscopic observations and supplemented them with the photometry from Gaia DR3 and other surveys. The optical spectra of this target show prominent emission lines, including highly ionized [Fe VII] and O VI lines. The cool component of this symbiotic binary is an M4-5 giant with T_eff ∼ 3 380 - 3 470 K and luminosity ∼3 × 10³ L⊙ (for the adopted distance of 3 kpc), the hot component is a shell-burning white dwarf. The photometric observations of the Gaia satellite, published recently in the Gaia DR3 suggested the variability with the period of about 700-800 days, that we tentatively attributed to the orbital motion of the binary.