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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], Comment: accepted in Astronomische Nachrichten / Astronomical Notes

Institute of Astronomy and National Astronomical Observatory, Bulgarian Academy of Sciences, 72 Tsarigradsko shose,BG-1784, Sofia, BulgariaReceived 2 September 2014, accepted 2014 Dec 04Published online 2015 Mar 01Key words Stars: binaries – novae, cataclysmic variables – binaries: symbiotic – stars: individual: T CrB, RS OphWe performed simultaneous observations in 3 bands (UBV)of the flickering variability of the recurrent novae RS Ophand T CrB at quiescence. Using new and published data, we compare the colours of the flickering in cataclysmic variablesand symbiotic recurrent novae. We find a difference between t he colours of the flickering source in these two types ofaccreting white dwarfs. The detected difference is highly significant with p−value≈2×10

We present new radial velocities of the high-mass X-ray binary star 4U 2206+54 based on optical spectra obtained with the Coude spectrograph at the 2 m RCC telescope of the Rozhen National Astronomical Observatory, Bulgaria in the period November 2011–July 2013. The radial velocity curve of the He I δ6678 A line is modeled with an orbital period Porb = 9.568 d and an eccentricity of e = 0.3. These new measurements of the radial velocity resolve the disagreements of the orbital period discussions. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)