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XHIP: An extended hipparcos compilation
Anderson, E.; Francis, Ch.
We present the Extended Hipparcos Compilation (XHIP), a database of all stars in the New Reduction of the Hipparcos Catalog extensively cross-referenced with data from a broad survey of presently available sources. The resulting collection uniquely assigns 116 096 spectral classifications, 46 392 radial velocities, and 18 549 homogenized iron abun…
Variations of the interstellar extinction law within the nearest kiloparsec
Gontcharov, G. A.
Multicolor photometry from the Tycho-2 and 2MASS catalogues for 11 990 OB and 30 671 K-type red giant branch stars is used to detect systematic large-scale variations of the interstellar extinction law within the nearest kiloparsec. The characteristic of the extinction law, the total-to-selective extinction ratio Rv, which also characterizes the s…
Estimation of the galactic spiral pattern speed from Cepheids
Bobylev, V. V.; Bajkova, A. T.
To study the peculiarities of the Galactic spiral density wave, we have analyzed the space velocities of Galactic Cepheids with propermotions from the Hipparcos catalog and line-of-sight velocities from various sources. First, based on the entire sample of 185 stars and taking R 0 = 8 kpc, we have found the components of the peculiar so…
Spatial distribution and kinematics of OB stars
Gontcharov, G. A.
The sample of 37 485 suspected OB stars selected by Gontcharov (2008) from the Tycho-2 catalogue has been cleaned of the stars that are not of spectral types OV-A0V. For this purpose, the apparent magnitude V T from Tycho-2, the absolute magnitude M_{V_T } calibrated as a function of the dereddened color index ( B T - V <…
Dependence of kinematics on the age of stars in the solar neighborhood
Gontcharov, G. A.
The variations of kinematic parameters with age are considered for a sample of 15 402 thin-disk O-F stars with accurate α, δ, µ, and π > 3 mas from the Hipparcos catalogue and radial velocities from the PCRV catalogue. The ages have been calculated from the positions of the stars on the Hertzsprung-Russell diagram relative to the isochrones fro…
Kinematics of stars in the northern and southern galactic hemispheres
Tsvetkov, A. S.; Vityazev, V. V.
We use vector spherical harmonics for a kinematic analysis of the proper motions of stars from the Hipparcos, Tycho-2, and UCAC3 catalogues in the northern and southern Galactic hemispheres. We have found that the statistically reliable values of the Ogorodnikov-Milne model parameters M {32/+} and M {32/-