E. A. Kolotilov

UBVJHKLM photometry of the symbiotic Mira V407 Cyg in 1998–2002

AbstractNew results of UBV JHKLM photometry of the symbiotic Mira V407 Cyg performed in 1998–2002 are reported. In 2002, these observations were supplemented with RI observations and a search for rapid variability in the V band. The hot component of V407 Cyg experienced a strong flare in 1998, which was the second in the history of photometric observations of this star; this flare is still continuing. During the flare, the spectral energy distribution of the hot component can be approximated by blackbody radiation with a temperature of ∼7200 K. At the maximum brightness, the bolometric flux from the hot component did not exceed 3% of the Miras mean bolometric flux, while its bolometric luminosity was ∼400L⊙. Appreciable variations of the stars BV brightness

Evolution of the symbiotic star AS 338 after its strong outburst in 1983

(\tilde0\mathop m\limits_. 7)

Photometric variability of the young star DI Cep

on a timescale of several days have been observed. These variations are not correlated with variations of B-V. Flickering on a timescale of several minutes with an amplitude of

UBV photometry of the classical symbiotic star BF Cygni

\tilde0\mathop m\limits_. 2

Photometric and spectrophotometric observations of the classical symbiotic star YY Her during its return to quiescence

has been detected in the V band. The observations suggest that the hot component can be in three qualitatively different states. In a model with a rapidly rotating white dwarf, these states can be associated with (i) the quiescent state of the white dwarf (with a very low accretion rate), (ii) an ejection state, and (iii) an accretion state. The Mira pulsation period P is