V. B. Puzin

Russian Academy of Sciences | RAS · Institute of Astronomy

New results of studying the variability of line profiles in the spectra of bright OBA stars on minute and second time scalesare presented. The observations were carried out in 2015–2021. Nearly 11000 spectra of 22 OBA stars were obtained. Regularvariations of the line profiles with minute periods and amplitudes of 1–2% of the continuum level in spect...

This article is a brief survey of our previous work devoted to searching for candidate type FK Com giant stars and an analysis of data for yet another new candidate, KIC 7732964. Establishing that KIC 7732964 belongs to this group of stars requires further study of the evolutionary status of the star (dwarf, subdwarf, or giant). The star has fast r...

In this work, modernized data acquisition systems of the Andyrchi and Carpet-3 shower facilities with automated data preprocessing and data transmission systems to the observatory of the Terskol Branch of the Institute of Astronomy are described. To solve joint problems on searching transient sources, data from the Andyrchi and Carpet facilities ar...

Analysis of collected photometric observations obtained with the Kepler Space Telescope were used to select and study 33 objects with parameters corresponding to those of the FK Com starHD199178; these can be considered candidate stars of this type. In this final study, the four objects with the best light curves, which show the properties of their...

We present the results of simultaneous spectroscopic and photometric observations of the cataclysmic variable star (hereafter CVs) V455 Andromedae, belonging to the WZ Sge sub-class, in quiescence. Using the spectroscopic data we computed time-resolved Doppler tomograms of the system demonstrating its behavior at different orbital phases. In the to...

We present an analysis of new photometric and spectropolarimetric observations of a chromospherically active star FKCom. Based on this observational data and the data from the literature sources, applying a common technique, we performed an analysis of a complete set of the available photometric data, which were divided into 218 individual light cu...

A mechanism for the formation of humps in the light curves of WZ Sge cataclysmic variables is proposed, based on the results of three-dimensional simulations of the gas dynamics in the V455 And system. Analysis of the computed flow structure shows the formation of an accretion disk and four shocks in the system, located at the outer edge of the dis...

Using the results of 3D gas dynamic numerical simulations we propose a mechanism that can explain the quiescent multihumped shape of light curves of WZ Sge short-period cataclysmic variable stars. Analysis of the obtained solutions shows that in the modeled system an accretion disk forms. In the outer regions of the disk four shock waves occur: two...

Context. Recent detection of a yellow supergiant star as a possible progenitor of a supernova has posed serious questions about our understanding of the evolution of massive stars. Aims. The spectroscopic binary star HD 50975 with an unseen hot secondary was studied in detail with the main goal of estimating fundamental parameters of both componen...

High-accuracy photometric observations obtained with the Kepler Space Telescope are used to identify candidate FK Com stars-a very rare group of single, rapidly rotating, chromospherically active G-K stars. Published data for more than 40 000 stars are used with available Kepler observations from the Q3 time interval to select four stars with tempe...

We present the results of our new spectropolarimetric observations of FKCom aimed to measure the longitudinal component B (z) of its magnetic field. The most interesting interpretation of our results suggests that the B (z) value has significantly decreased compared to the 2008 observations of this star. Such a decrease of the longitudinal componen...

We present the results of spectroscopic observations and Doppler tomography of the short-period cataclysmic variable star V455 And. The investigated spectra indicate that the disk in the system periodically changes its size. Besides, we suppose that there is a dense region in the disk, moving in the retrograde precession. This region can periodic...