Search Publications
Simultaneous X-ray/UV Observations of Ultraluminous X-ray Source Holmberg II X-1 with Indian Space Mission Astrosat
Vinokurov, A.; Solovyeva, Y.; Atapin, K. +11 more
We present the results of eight epochs of simultaneous UV and X-ray observations of the highly variable ultraluminous X-ray source (ULX) Holmberg II X-1 with AstroSat—Indian multiwavelength space satellite. During the entire observation period from late 2016 to early 2020, Holmberg II X-1 showed a moderate X-ray luminosity about of
Discovery of New δ Scuti Stars
Kιrmιzιtaş, Ö.; Çavuş, S.; Aliçavuş, F. Kahraman
—Pulsating stars are remarkable objects for stellar astrophysics. Their pulsation frequencies allow us to probe the internal structure of stars. One of the most known groups of pulsating stars is
Detailed Spectroscopy of Post-AGB Supergiant GSC 04050–02366 in IRAS Z02229+6208 IR Source System
Klochkova, V. G.; Panchuk, V. E.
—In the optical spectra of the cold post-AGB supergiant GSC
Tidal Constraints for Wide Binaries in Pleiades
Danilov, V. M.
—A technique is proposed for estimating the parameters of spatial orientation of the
Activity of the Young Star TOI 837 with an Exoplanet
Savanov, I. S.
—Based on high-precision data from the archive of the TESS space mission, a study was made of the photometric brightness variability of TOI 837—a young star with an exoplanet, a member of the southern sky cluster IC 2602. Based on all available observational results, we have estimated the star's rotation period and brightness variability amplitude…
Mass of the Asteroid (7348) 1993FJ22 as Determined by the Dynamic Method
Kuznetsov, V. B.; Chernetenko, Yu. A.
—The mass of the asteroid (
Photometric Study of the Open Cluster NGC 225
Carraro, G.; Ikonnikova, N. P.; Yalyalieva, L. N. +2 more
—NGC 225 is a young moderately populated cluster with discrepant age, distance, and color excess estimates reported by different authors. We combine our photometry with the data from large surveys (2MASS, WISE, Pan-STARRS) to derive the parameters of NGC 225 and study the extinction law in the near infrared in the direction of the cluster. We use …
Ultraluminous X-Ray Sources
Fabrika, S. N.; Atapin, K. E.; Vinokurov, A. S. +1 more
Ultraluminous X-ray sources (ULXs) were identified as a separate class of objects in 2000 based on data from the Chandra X-Ray Observatory. These are unique objects: their X-ray luminosities exceed the Eddington limit for a typical stellar-mass black hole. For a long time, the nature of ULXs remained unclear. However, the gradual accumulation of d…
Magnetic Fields of CP Stars in the Orion OB1 Association. V. Stars of Subgroups (c) and (d)
Romanyuk, I. I.; Semenko, E. A.; Moiseeva, A. V. +2 more
—The paper presents the results of magnetic field measurements of 27 chemically peculiar stars in subgroups (c) and (d) of the Orion OB1 association. In total, more than 140 circularly polarized spectra were obtained and measured in the period from 2013 to 2020. An analysis of the results showed that 13 out of 24 CP stars in subgroup (c) have a ma…
Precise Masses, Ages, and Orbital Parameters of the Binary Systems HIP 11352, HIP 70973, and HIP 72479
Al-Wardat, M. A.; Al-Tawalbeh, Y. M.; Hussein, A. M. +7 more
In this work, the orbital elements are improved and the total masses of the three close visual binary systems CVBSs: HIP 11352, HIP 70973, and HIP 72479 are precisely calculated. The calculations were performed based on an assessment of the latest Gaia DR2 and Hipparcos trigonometric parallax measurements. The morphology and kinematics of orbits a…