Search Publications
Analysis of Selected Runaway Stars in the Orion Nebula Based on Data from the Gaia EDR3 Catalogue
Bobylev, V. V.; Bajkova, A. T.
We have performed Monte Carlo simulations of the trajectories of several runaway stars using their parallaxes and proper motions from the Gaia EDR3 catalogue. We have confirmed the hypothesis that the stars AE Aur and $µ$ Col are a product of the multiple system breakup ${∼}2.5$ Myr ago and the Orion Trapezium may be the parent cluster for t…
Orbits of Visual Double Stars from P. Couteau's Catalogue Determined with Gaia DR2 and Gaia EDR3 Data
Kisser, A. E.; Krechet, V. G.
The orbits of ten stars discovered by P. Couteau have been determined for the first time: COU 99, 357, 610, 850, 1346, 1531, 1642, 1752, 1845, and 2459. For two of them (COU 850 and 1752) an arc of more than half a revolution is covered by observations; the orbits of the remaining stars have been determined from short arcs ($5^{\circ}{-}50^{\circ}…
Orbits and Structure of the Quadruple Systems GJ 225.1 and FIN 332
Tokovinin, A.
Only a handful of quadruple systems with two accurate inner visual orbits are known. The architecture of two such systems is studied here to determine the period ratios, mutual orbit orientation, and other parameters; updated orbital elements and their errors are derived. Gliese 225.1 (HIP 28442) is composed of three K-type and one M-type dwarfs a…
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…
Systematic error of the Gaia DR1 TGAS parallaxes from data for the red giant clump
Gontcharov, G. A.
Based on the Gaia DR1 TGAS parallaxes and photometry from the Tycho-2, Gaia, 2MASS, andWISE catalogues, we have produced a sample of 100 000 clump red giants within 800 pc of the Sun. The systematic variations of the mode of their absolute magnitude as a function of the distance, magnitude, and other parameters have been analyzed. We show that the…
Properties of the Tycho-2 catalogue from Gaia data release
Tsvetkov, A. S.; Vityazev, V. V.; Petrov, S. D. +2 more
Based on the measurements performed in the first 14 months of Gaia operation, we have solved the problem of obtaining the systematic differences between the stellar positions and proper motions of the TGAS (Tycho-Gaia Astrometric Solution) and Tycho-2 catalogues. By dividing the common stars from the TGAS and Tycho-2 catalogues into three G-magnit…
Spectroscopic studies of yellow supergiants in the Cepheid instability strip
Usenko, I. A.
High-resolution spectra of nine yellow nonvariable supergiants (NVSs) located within the canonical Cepheid instability strip from Sandage and Tammann (1969) ( α Aqr, ɛ Leo, µ Per, ω Gem, BD+60 2532, HD 172365, HD 187299, HD 190113, and HD 200102) were taken with the 1-m Zeiss and 6-m BTA telescopes at the Special Astrophysical Observatory of…
Extinction law at a distance up to 25 kpc toward the Galactic poles
Gontcharov, G. A.
Photometry from the Tycho-2, 2MASS, andWISE catalogues for clump and branch giants at a distance up to 25 kpc toward the Galactic poles has allowed the variations of various characteristics of the infrared interstellar extinction law with distance to be analyzed. The results obtained by the extinction law extrapolation method are consistent for di…
Residual HCRF rotation relative to the inertial coordinate system
Bobylev, V. V.
VLBI measurements of the absolute proper motions of 23 radio stars have been collected from published data. These are stars with maser emission, or very young stars, or asymptotic-giant-branch stars. By comparing these measurements with the stellar proper motions from the optical catalogs of the Hipparcos Celestial Reference Frame (HCRF), we have …