Search Publications
HD 181906: A star with two systems of active longitudes on its surface
Savanov, I. S.
We use continuous 156-day COROT photometric observations of the F dwarf HD 181906 to analyze temperature inhomogeneities on the stellar surface and follow their evolution. The analysis used the iPH code, which solves for the temperature inhomogeneities in a two-temperature approximation without any assumptions about the shape or number of spots on…
A dynamical study of 12 wide visual binaries
Romanenko, L. G.; Kalinichenko, O. A.; Kisselev, A. A.
We have carried out the first dynamical studies of the relative motions of the components of 12 wide binaries: ADS 497, ADS 2427 (GL 130.1), ADS 3593, ADS 5436, ADS 6646, ADS 6783, ADS 9559 ( δ Boo), ADS 10329, ADS 10759 ( ψ Dra), ADS 14878, ADS 15229, and ADS 16558. The analysis is based on series of photographic observations made with the 26-inc…
A dynamical study of the wide hierarchic triple star ADS 10288
Kiselev, A. A.; Romanenko, L. G.; Gorynya, N. A.
We have performed the first dynamical study of the relative motions of the components of the wide hierarchic triple star system ADS 10288 (GL 649.1 = WDS 16579+4722), based on a 15-year series of photographic observations with the 26″ Pulkovo refractor, supplemented with data from the WDS catalog, HIPPARCOS parallaxes, and radial velocities of the…
Apex diagrams for the stellar population of the solar neighborhood
Vereshchagin, S. V.; Reva, V. G.; Chupina, N. V.
We have studied some kinematic features of the coronas of near-solar stellar streams, based on Hipparcos observations. Apex diagrams for kinematic streams, open clusters, and field stars are plotted. In our analysis, we used the apex-diagram (AD) method we developed earlier. We find that the Eggen streams and Arcturus stream have similar propertie…
The structure of the AD diagram for the hyades cluster
Vereshchagin, S. V.; Reva, V. G.; Chupina, N. V.
The Hyades Cluster is used to analyze details of the AD-diagram method developed in our earlier works and applied to the corona of the Ursa Major stream. Hipparcos data are used to analyze the kinematics of the Hyades Cluster and determine its apex. Evidence for rotation of the cluster is presented.
A study of the X-ray pulsars X1845-024 and XTE J1858+034 based on INTEGRAL observations
Doroshenko, V. A.; Doroshenko, R. F.; Postnov, K. A. +2 more
We present an analysis of observations of the relatively unstudied X-ray pulsars X1845-024 and XTE J1858+034 carried out from May 2003 through November 2004 using the JEM-X and IBIS telescopes of the INTEGRAL international gamma-ray observatory at energies of 5-70 keV. The X-ray spectra and light curves of the pulsars are constructed. During the o…
Stellar subsystems of the galaxy NGC 2366
Tikhonov, N. A.; Galazutdinova, O. A.
Hubble Space Telescope archive data are used to perform photometry of stars in seven fields at the center and periphery of the galaxy NGC 2366. The variation of the number density of stars of various ages with galactocentric radius and along the minor axis of the galaxy are determined. The boundaries of the thin and thick disks of the galaxy are f…
Variations of the parameters of the dust envelope of the symbiotic star CH Cygni
Bogdanov, M. B.; Taranova, O. G.
The results of JHKLM photometry of the symbiotic star CH Cyg are presented. These demonstrate that, in Autumn 2006, the state of maximum near-IR brightness observed in 2003 2006 was replaced by a sharp brightness decline in all wavebands. One possible explanation is a sharp increase in the density of circumstellar dust envelope. The JHKLM photomet…
Coronal mass ejection of April 27, 2003, and evolution of the active region NOAA 10338 in the radio
Kardapolova, N. N.; Borisevich, T. P.; Peterova, N. G. +1 more
The results of a study of the coronal mass ejection (CME) of April 27, 2003, which was intrinsically associated with the active region NOAA 10338, are reported. Particular attention is paid to the initial stage of the event, which was accompanied by X-ray bursts of class C9.3 and C6.7, with the aim of determining the origin of CMEs. The energy sou…
Some properties of the latitude brightness distributions in the K and F coronae according to SOHO/LASCO data
Fainshtein, V. G.
We have obtained continuous latitude distributions of the K and F corona brightnesses at various distances for the first time, using both the Hayes—Vourlidas—Howard method and our own recently proposed, simple technique for separating the emission of the K and F coronas. Data from the LASCO C2 and C3 coronagraphs are analyzed. Variations of the an…