B. F. Yudin

Discovery of a bipolar and highly variable mass outflow from the symbiotic binary StHα 190

A highly and rapidly variable bipolar mass outflow from StHa 190 has been discovered, the first time in a yellow symbiotic star. Permitted emission lines are flanked by symmetrical jet features and multi-component P-Cyg profiles, with velocities up to 300 km/sec. Given the high orbital inclination of the binary, if the jets leave the system nearly perpendicular to the orbital plane, the de-projected velocity equals or exceeds the escape velocity (1000 km/sec). StHa190 looks quite peculiar in many other respects: the hot component is an O-type sub-dwarf without an accretion disk or a veiling nebular continuum and the cool component is a G7 III star rotating at a spectacular 105 km/sec unseen by a large margin in field G giants.A highly and rapidly variable bipolar mass outflow from StH 190 has been discovered, the rst time in a yellow symbiotic star. Permitted emission lines are flanked by symmetrical jet features and multi-component P-Cyg proles, with velocities up to 300 km s 1 . Given the high orbital inclination of the binary, if the jets leave the system nearly perpendicular to the orbital plane, the de-projected velocity equals or exceeds the escape velocity (1000 km s 1 ). StH 190 looks quite peculiar in many other respects: the hot component is an O-type sub-dwarf without an accretion disk or a veiling nebular continuum and the cool component is a G7 III star rotating at a spectacular 105 km s 1 , unseen by a large margin in eld G giants.

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

JHK-band spectro-interferometry of T Cep with the IOTA interferometer

(\tilde0\mathop m\limits_. 7)

Infrared observations of the star R Cas

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

Observations of Mira stars with the IOTA/FLUOR interferometer and comparison with Mira star models

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IR photometry of the symbiotic star BF Cyg: Detection of the red giant’s ellipsoidal brightness variability

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