Search Publications
Testing the Distance Scale of the Gaia TGAS Catalogue by the Kinematic Method
Bobylev, V. V.; Bajkova, A. T.
We have studied the simultaneous and separate solutions of the basic kinematic equations obtained using the stellar velocities calculated on the basis of data from the Gaia TGAS and RAVE5 catalogues. By comparing the values of Ω'0 found by separately analyzing only the line-of-sight velocities of stars and only their proper motions, we …
Searching for the Young Kinematic Group Associated with HD 166191
Eselevich, M. V.; Sokolov, I. V.; Potravnov, I. S. +1 more
We present the results of our search for the stars kinematically related to the young star HD 166191 surrounded by a warm dust disk. Using data from the GAIA DR1, 2RXS, ALLWISE catalogues and confirming optical spectroscopy, we have identified five stars of age 10 Myr with similar kinematics in a sky region of radius 11° on the periphery of the Sc…
Single X-ray Bursts and the Model of a Spreading Layer of Accreting Matter over the Neutron Star Surface
Grebenev, S. A.; Chelovekov, I. V.
The excess of the rate of type I X-ray bursts over that expected when the matter fallen between bursts completely burns out in a thermonuclear explosion which is observed in bursters with a high persistent luminosity (4 × 1036 ≲ L X ≲ 2 × 1037 erg s-1) is explained in terms of the model of a spreading …
Kinematics and Dynamics of the Galactic Halo from RR Lyrae Variable Stars
Dambis, A. K.; Zhao, G.; Rastorguev, A. S. +3 more
Based on a sample of RR Lyrae variable stars including more than 9000 objects with proper motions and distances, we have investigated the kinematics of the Galactic halo from the two-dimensional velocity field. We have used both the proper motions deduced independently by us from the positional data taken from all-sky catalogues in a time interval…
New Features of Parenago's Discontinuity from Gaia DR1 Data
Tsvetkov, A. S.; Vityazev, V. V.; Popov, A. V. +3 more
The velocity field of main-sequence stars and red giants from the TGAS catalogue with heliocentric distances up to 1.5 kpc has been analyzed for various spectral types. To estimate the influence of a low accuracy of stellar parallax measurements on the results of a kinematic analysis of distant stars, first we have studied in detail how the kinema…
Kinematics of B-F Stars as a Function of Their Dereddened Color from Gaia and PCRV Data
Gontcharov, G. A.
Parallaxes with an accuracy better than 10% and proper motions from the Gaia DR1 TGAS catalogue, radial velocities from the Pulkovo Compilation of Radial Velocities (PCRV), accurate Tycho-2 photometry, theoretical PARSEC, MIST, YaPSI, BaSTI isochrones, and the most accurate reddening and interstellar extinction estimates have been used to analyze …
Analysis of the Systematic Differences between the Stellar Parallaxes of the TGAS and Hipparcos Catalogues Using Spherical Harmonics
Tsvetkov, A. S.; Amosov, F. A.
The systematic differences between the trigonometric parallaxes of the Hipparcos and TGAS catalogues have been investigated using spherical harmonics. The most significant harmonics in the expansion have been determined. The distribution of the parallax difference dispersion in various regions of the celestial sphere has also been studied. The dis…
Results of Photometric and Spectroscopic Observations of the Young Variable Star V730 Cep
Grinin, V. P.; Mkrtichian, D.; Potravnov, I. S. +1 more
We present the results of our photometric ( V RI) and spectroscopic observations of the young variable star V730 Cep (MisV1147) classified by Uemura et al. (2004) as a Herbig Be star. Our photometry confirms the conclusion of the above authors that this star has a complex pattern of variability including periodic or quasi-periodic brightness varia…