A photometric and spectroscopic study of the eclipsing symbiotic binary AX Persei

We analysed photometric and spectroscopic optical observations of the eclipsing symbiotic binary AX Persei. For the first time, we present and discuss its historical, 1887-1999, photographic/B-band and visual light curve (LC). The red giant in AX Per losses mass via the wind at a rate of M = 7.4 ± 1.7 10-7 M [dot in circle] yr-1. The terminal velocity of the wind is v infinity = 32 ± 6 km s-1. We estimated an effective radius of the H II nebula during the post-outburst state (to JD 2450000) to be of Rn = 192 ± 25 R [dot in circle] and its average electron concentration ne = (2.9 - 3.6) ± 0.7 109 cm-3 for the electron temperature Te = 1-1.5 104 K. The [O III] nebula in AX Per is rather dense, having the electron concentration ne([O III]) approximately equals 3 107 cm-3 for Te = 1-1.5 104 K. Spectroscopic observations made in the middle of the 1992.8 and 1994.7 eclipses showed that a significant part of flux emitted in the H I, He II and nebular [O III] lines originates in the vicinity of the hot component. Transition of AX Per to its nebular phase occurred at/around JD 2450000. A small [similar to] 0.6 mag brightening at that time and consequently very broad wave-like variation in the LC developed. This event was caused by dilution of a shell around the hot star, during which about of 1.5 1050 particles ( [similar to] 1.3 10-7 M [dot in circle] ) were injected into the ionized region.