Search Publications
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 …
Radial velocity dispersions of star groups in M 67
Vereshchagin, S. V.; Chupina, N. V.
High-precision measurements of radial velocities of the M 67 cluster members are used to calculate the radial-velocity dispersions in the stellar groups found earlier in the cluster's corona. The previously detected feature in one of the groups (Group 60) consisting of stars with almost identical space velocities was confirmed. The possibility of …
Unusual objects in the spiral galaxy NGC 6946
Efremov, Yu. N.
Several strange objects in the spiral galaxy NGC 6946 are described. One of these objects is the giant stellar complex noted long ago; we suggested that its sharp semicircular western edge is a result of the ram pressure, arising owing to motion of this complex through the H I halo of NGC 6946. We found another enigmatic object, proposing for it t…
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…
A young star cluster in the Leo A galaxy
Narbutis, D.; Vansevičius, V.; Bridžius, A. +2 more
We report a serendipitous discovery of a star cluster in the dwarf irregular galaxy Leo A. Young age ( ∼28 Myr) and low mass ( ∼510 M⊙) estimates are based on the isochrone fit assuming a metallicity derived for H II regions (Z=0.0007). The color-magnitude diagrams of the stars, located in and around the cluster area, and the results of…
Ultraviolet spectroscopic investigation of HU Aqr and AN UMa with the data from HST and IUE
Sanad, M. R.
We present ultraviolet spectroscopic study of two polar systems, HU Aqr and AN UMa, observed with the Hubble Space Telescope's Space Telescope Imaging Spectrograph (STIS) and Faint Object Spectrograph (FOS) and with the International Ultraviolet Explorer (IUE) during the period 1979--2003, to diagnose the ultraviolet fluxes of C IV 1550 Å and He I…
Structural and morphological properties of ultraluminous infrared galaxies at 1<z<3
Fang, Guanwen; Kong, Xu; Chen, Yang +1 more
Using the Hubble Space Telescope (HST)/Wide Field Camera 3 (WFC3) near-infrared high-resolution imaging from the 3D-HST survey, we analyze the morphology and structure of 502 ultraluminous infrared galaxies (ULIRGs; LIR>1012L⊙) at 1<z< 3. Their rest-frame optical morphologies show that high-redshift ULIRGs…
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…
Pulsation of IU Per from the Ground-based and `Integral' Photometry
Gális, R.; Kundra, E.; Hric, L.
IU Per is an eclipsing semi-detached binary with a pulsating component. Using our own ground-based, as well as INTEGRAL satellite photometric observations in the B and V passbands, we derived geometrical and physical parameters of this system. We detected the short-term variations of IU Per in the residuals of brightness after the subtraction of s…