Search Publications
On the Properties of the Galactic Dust Layer within 700 pc of the Sun
Gontcharov, G. A.
We compare the spatial stellar color variations with our three-dimensional analytical model of the spatial dust distribution to refine the properties of the dust layer in Galactic solar neighborhoods. We use a complete sample of 93 992 clump giants with a small admixture of branch giants from the Gaia DR2 catalogue in a spatial cylinder with a rad…
Kinematic Parameters of the Stellar Velocity Field within 3 kpc of the Sun Based on the Gaia Data Release 2 with Radial Velocities Catalogue
Tsvetkov, A. S.; Amosov, F. A.
The paper is devoted to determining the parameters of the three-dimensional Ogorodnikov—Milne kinematic model based on the Gaia DR2 star catalogue (the subset of seven million stars containing radial velocities). The behavior of the parameters as a function of the distance to stars is studied. The parameters derived from the stellar proper motions…
The Circumstellar Envelope of the Semiregular Variable Star V CVn
Lamzin, S. A.; Rastorguev, A. S.; Safonov, B. S. +1 more
V CVn is a red semiregular variable star with an amplitude of its V-band brightness variations of ≈2 m . An unusually high amplitude of its polarization variability, up to 6%, a noticeable inverse correlation between polarization and total flux, and relative constancy of the angle of polarization distinguish this star from other semireg…
Search for Evolutionary Changes in the Periods of Cepheids: V1033 Cyg, a Classical Cepheid at the First Crossing of the Instability Strip
Lemasle, B.; Berdnikov, L. N.; Kniazev, A. Yu. +9 more
For the classical Cepheid V1033 Cyg we have constructed an O—C diagram spanning a time interval of 117 years. The O—C diagram has the shape of a parabola, which has made it possible to determine for the first time the quadratic light elements and to calculate the rate of evolutionary increase in the period dP/dt = 18.19 (±0.08) syr-1, i…
Edge-on Galaxies in the Hubble Ultra Deep Field
Savchenko, S. S.; Reshetnikov, V. P.; Usachev, P. A.
We have produced a sample of 58 edge-on spiral galaxies at redshifts z 1 selected in the Hubble Ultra Deep Field. For all galaxies we have analyzed the 2D brightness distributions in the V 606 and i 775 filters and measured the radial ( h r ) and vertical ( h z ) exponential scale lengths of the bright…
Search for Evolutionary Changes in the Periods of Cepheids: BY Cas
Berdnikov, L. N.
For the low-amplitude Cepheid BY Cas we have constructed an O - C diagram spanning a time interval 123 years. The O - C diagram has the shape of a parabola, which has made it possible to determine for the first time the quadratic light elements and to calculate the rate of evolutionary increase in the period, dP/dt = +0.985 (±0.091) s yr-1
Search for Evolutionary Changes in the Periods of Cepheids: V532 Cyg
Berdnikov, L. N.
For the low-amplitude Cepheid V532 Cyg we have constructed an O - C diagram spanning a time interval of 121 years. The O - C diagram has the shape of a parabola, which has made it possible to determine for the first time the quadratic light elements and to calculate the rate of evolutionary decrease in the period, dP/dt = -0.248 (±0.067) s yr…
Kinematics of Hot Subdwarfs from the Gaia DR2 Catalogue
Bobylev, V. V.; Bajkova, A. T.
We have studied the kinematic properties of the candidates for hot subdwarfs (HSDs) selected by Geier et al. from theGaiaDR2 catalogue. We have used a total of 12 515 stars with relative trigonometric parallax errors less than 30%. The HSDs are shown to have different kinematics, depending on their positions on the celestial sphere. For example, t…
Investigation of the Outburst Activity of the Black Hole Candidate GRS 1739-278
Lutovinov, A. A.; Mereminskiy, I. A.; Filippova, E. V. +2 more
We have performed a joint spectral and timing analysis of the outburst of GRS 1739-278 in 2014 based on Swift and INTEGRAL data. We show that during this outburst the system exhibited both intermediate states: hard and soft. Peaks of quasi-periodic oscillations (QPOs) in the frequency range 0.1-5 Hz classified as type-C QPOs have been detected fro…
Search for Evolutionary Changes in the Periods of Cepheids: CF Cas
Berdnikov, L. N.; Pastukhova, E. N.
For the classical Cepheid CF Cas we have constructed an O- C diagram spanning a time interval of 129 years. The O- C diagram has the shape of a parabola, which has made it possible to determine for the first time the quadratic light elements and to calculate the rate of evolutionary decrease in the period, dP/ dt = -0.050 (±0.006) syr-1…