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Astronomical surveys and big data
Mickaelian, Areg M.
Recent all-sky and large-area astronomical surveys and their catalogued data over the whole range of electromagnetic spectrum, from γ -rays to radio waves, are reviewed, including such as Fermi-GLAST and INTEGRAL in γ -ray, ROSAT, XMM and Chandra in X-ray, GALEX in UV, SDSS and several POSS I and POSS II-based catalogues (APM, MAPS, USNO, GSC) in …
Visual binaries: cross-matching and compiling of a comprehensive list
Kovaleva, D. A.; Malkov, O. Yu.; Isaeva, A. A.
Visual binary stars make up the largest set among observed types of binaries (currently more than 110 000 systems are known containing more than 230 000 components). However, statistical analysis of this sample is a complicated task because a number of catalogues of visual binaries contain various data for evidently overlapping sets of objects. To…
A new estimate of the Local Standard of Rest from data on young objects
Bobylev, V. V.; Bajkova, A. T.
To estimate the peculiar velocity of the Sun with respect to the Local Standard of Rest (LSR), we use young objects in the Solar neighborhood with distance measurement errors within 10%--15%. These objects include the nearest Hipparcos O--B2.5 type stars, masers with VLBI trigonometric parallaxes, and two samples consisting of the youngest and mid…
Peculiarities and Variations in the Optical Spectrum of the RV Tauri-type Star R Sct
Kipper, Tõnu; Klochkova, Valentina G.
We analyzed some new high resolution optical spectra of the semiregular RV Tauri-type star R Sct. Fundamental parameters were found to be Teff=4500 K, log g=0.0 and ξt=4.0 km s-1. The results of chemical analysis show that R Sct is a metal-poor star with [Fe/H]≈-0.5. The carbon content with respect to iron is signi…
The Lower Main Sequence of Stars in the Solar Neighborhood: Model Predictions versus Observation
Sperauskas, J.; Bartašiūtė, S.; Deveikis, V. +1 more
We have used the Simbad database and VizieR catalogue access tools to construct the observational color--absolute magnitude diagrams of nearby K--M dwarfs with precise Hipparcos parallaxes (σ π /π ≤ 0.05). Particular attention has been paid to removing unresolved double/multiple stars and variables. In addition to archival data, we have…
Period Change, Spot Migration and Orbital Solution for the Eclipsing Binary AR Lac
Munari, U.; Siviero, A.; Dallaporta, S.
We present a new large set of photoelectric photometric measurements (1806 in V and 1367 in B passbands) of the eclipsing RS CVn-type system AR Lac covering the period 2000 June 28 to 2005 October 13. 13 new epochs of minima have been derived that allows us to update the complex O--C pattern of this binary, now monitored for more than a hundred ye…
Radial Velocities of Population II Binary Stars. Ii.
Bartkevičius, A.; Sperauskas, J.
Here we publish the second list of radial velocities for 91 Hipparcos stars, mostly high transverse velocity binaries without previous radial velocity measurements. The measurements of radial velocities are done with a CORAVEL-type radial velocity spectrometer with an accuracy better than 1 km/s. We also present the information on eight new radial…
On a New Technique for Discovering Variable Stars
Mironov, A. V.; Zakharov, A. I.; Nikolaev, F. N.
A technique for discovering variable stars based on the calculation of the correlation coefficients is proposed. Applications of the technique are shown on the results of numerical experiments and on the Hipparcos photometric data.
High Precision with the Whole Earth Telescope: Lessons and Some Results from XCov20 for the roAp Star HR 1217
Kepler, S. O.; Kawaler, S. D.; Winget, D. E. +41 more
HR 1217 is a prototypical rapidly oscillating Ap star that has presented a test to the theory of nonradial stellar pulsation. Prior observations showed a clear pattern of five modes with alternating frequency spacings of 33.3 mu Hz and 34.6 mu Hz, with a sixth mode at a problematic spacing of 50.0 mu Hz (which equals 1.5 times 33.3 mu Hz) to the h…
Calibration of the Strömvil Photometric System
Sperauskas, J.; Straižys, V.; Boyle, R. P. +4 more
A calibration of color indices of the Strömvil photometric system in terms of physical parameters of stars is presented. The calibration is based on photoelectric photometry of about 1000 stars with known effective temperatures, distances, gravities and metallicities. The observations were accomplished in 2000--2003 with the 1.5 meter telescope of…