Search Publications
A Three-Dimensional Analytical Model of the Interstellar Extinction within the Nearest Kiloparsec
Savchenko, S. S.; Gontcharov, G. A.; Il'in, V. B. +6 more
We present a new version of our analytical model of the spatial interstellar extinction variations within the nearest kiloparsec from the Sun. This model treats the three-dimensional (3D) dust distribution as a superposition of three overlapping layers: (1) the layer along the Galactic midplane, (2) the layer in the Gould Belt, and (3) the layer p…
Link between the Optical and Radio Frames from Gaia DR3 Data and VLBI Measurements
Bobylev, V. V.
Based on published data, we have assembled a sample of 126 radio stars with the trigonometric parallaxes and proper motions measured by VLBI and available in the Gaia DR3 catalogue (in fact, Gaia EDR3). Our analysis of the Gaia-VLBI proper motion differences for 84 radio stars based on the model of solid-body mutual rotation has revealed no rotati…
Study of the X-ray Pulsar IGR J21343+4738 Based on NuSTAR, Swift, and SRG Data
Lutovinov, A. A.; Molkov, S. V.; Semena, A. N. +1 more
We present the results of our study of the X-ray pulsar IGR J21343+4738 based on NuSTAR, Swift, and SRG observations in the wide energy range 0.3-79 keV. The absence of absorption features in the energy spectra of the source, both averaged and phase-resolved ones, has allowed us to estimate the upper and lower limits on the magnetic field of the n…
FG Sge: New Multicolor Photometry and Short-Term Dust Shell Clearing in 2019
Arkhipova, V. P.; Ikonnikova, N. P.; Tatarnikov, A. M. +6 more
We present the results of a new stage of the long-term photometric study of FG Sge which is a quickly evolving central star of the planetary nebula Hen 1-5. Our new observations carried out on the SAI MSU telescopes in the optical ($BVRCIC$) and infrared (IR) ($JHKLM$) regions in 2008-2021 and 2013-2021, respectively, allowed…
Kinematics of OB Stars with Data from the LAMOST and Gaia Catalogues
Bobylev, V. V.; Bajkova, A. T.; Karelin, G. M.
We have analyzed the kinematics of OB stars from the list by Xiang et al. (2021) that contains ${∼}13 000$ single OB stars. For these stars there are photometric distance estimates and proper motions from the Gaia catalogue and line-of-sight velocities from the LAMOST catalogue. Based on a sample of single OB stars and using the photometric distan…
Influence of Active Regions on Solar Wind Characteristics at the Cycle Maximum
Reva, A. A.; Kirichenko, A. S.; Ulyanov, A. S. +2 more
Active regions (ARs) on the Sun are discussed as a possible source of the slow solar wind (SW) whose origin is still a subject of debates. In this paper we present experimental evidence for the possible influence of ARs on the SW speed and temperature near the maximum of solar cycle 23 (2000-2002). We have studied separately the characteristics of…
SRG/eROSITA Survey in the Lockman Hole: Classification of X-ray Sources
Gilfanov, M. R.; Belvedersky, M. I.; Bykov, S. D.
We have classified the X-ray sources detected by the SRG/eROSITA telescope in the deep Lockman Hole survey. The goal of the classification has been the separation of the sources into Galactic and extragalactic objects. For this purpose, we have used the results of our previous cross-match of X-ray sources with optical catalogs. For the classificat…
The First Light Curve Solutions and Period Study of BQ Ari
Akyuz, A.; Aksaker, N.; Poro, A. +14 more
The first analysis of the photometric observation in BVR filters of a W UMa type binary system BQ Ari was performed. Light curve analysis was performed using Wilson-Devinney (W-D) code combined with a Monte Carlo (MC) simulation to determine its photometric and geometric elements and their uncertainties. These results show that BQ Ari is a contact…
Study of Close Stellar Encounters with the Solar System Based on Data from the Gaia EDR3 Catalogue
Bobylev, V. V.; Bajkova, A. T.
We have studied stellar candidates for close (within 1 pc) encounters with the Solar system. For all of the stars under consideration the kinematic characteristics have been taken from the Gaia EDR3 catalogue. The parameters of the encounters of these stars with the Solar system have been calculated using three methods: (1) the linear one, (2) by …
Spectroscopic Redshift Determination for a Sample of Distant Quasars Detected by the SRG Observatory Based on RTT-150 Observations. II
Irtuganov, E. N.; Bikmaev, I. F.; Gilfanov, M. R. +16 more
Results of the spectroscopic observations at the 1.5-m Russian-Turkish telescope for another group of 12 X-ray sources discovered by the eROSITA telescope onboard the SRG space observatory and identified by the SRGz machine learning system as candidates for distant X-ray quasars are presented. Ten objects have been confirmed as quasars at redshift…