The symbiotic binary ZZ CMi: intranight variability and suggested outbursting nature

Abstract

We present photometric and spectral observations of the symbiotic star ZZ CMi. We detect intranight variability - flickering and smooth variations in U band. The amplitude of the flickering is about 0.10-0.20 mag in U band. In the B band the variability is lower, with amplitude less than 0.03 mag. We also detect variability in the H-alpha and H-beta emission lines, and find an indication for outflow with velocity of about 120-150 km/s. The results indicate that ZZ CMi is an accretion powered symbiotic containing an M4-M6 III cool component with an white dwarf resembling recurrent novae and jet-ejecting symbiotic stars. [The data are available on www.astro.bas.bg/~rz/ZZCMi/ZZCMi.tar.gz]