Search Publications
Search for Evolutionary Changes in the Periods of the Cepheids CEa Cas and CEb Cas
Berdnikov, L. N.; Pastukhova, E. N.; Ikonnikova, N. P. +4 more
For two classical Cepheids, CEa Cas and CEb Cas, members of the open cluster NGC 7790, we have constructed $O-C$ diagrams spanning a time interval of 125 years. The $O-C$ diagrams have the shape of parabolas, which has allowed us for the first time to determine the quadratic light elements and to calculate the rates of evolutionary changes in thei…
Search for Magnetars in the Galaxy M31 as Periodic X-ray Sources Based on XMM-Newton Data
Popov, S. B.; Pshirkov, M. S.; Zolotukhin, I. Yu.
Several years ago a series of powerful millisecond radio bursts with close dispersion measures was detected toward the galaxy M31. Taking the hypothesis about the possible association of these radio bursts with a magnetar in M31 as a starting point, we have searched for periodic X-ray signal sources using data from the XMM-Newton X-ray telescope. …
Multicolor Photometry and Peculiarities of the Spectrum for the post-AGB Candidate AU Vulpeculae (IRAS 20160+2734)
Esipov, V. F.; Ikonnikova, N. P.; Tatarnikov, A. M. +7 more
We present the results of a UBVRcIc and JHKLM photometric monitoring campaign conducted in 2016-2020, low-resolution spectroscopy, and an analysis of the ASAS-3 and ASAS-SN photometric data for the semiregular variable and post-AGB candidate AU Vul (IRAS 20160+2734). The star is shown to experience quasi-periodic brightness oscillations with a var…
MLS120126:042313+212951—A New Eclipsing Cataclysmic Variable in the Period Gap
Kolbin, A. I.; Aitov, V. N.; Kotov, S. S. +2 more
We have analyzed our photometric and spectroscopic observations of the new eclipsing cataclysmic variable MLS120126:042313+212951. We have found the system's orbital period $P=0.1034329$ day (${≈}2.48$ h) corresponding to the gap $2\lesssim P\lesssim 3$ h in the distribution of cataclysmic variables. A Doppler tomogram in the H$β$ line demonstrate…
Orbits of Visual Double Stars from P. Couteau's Catalogue Determined with Gaia DR2 and Gaia EDR3 Data
Kisser, A. E.; Krechet, V. G.
The orbits of ten stars discovered by P. Couteau have been determined for the first time: COU 99, 357, 610, 850, 1346, 1531, 1642, 1752, 1845, and 2459. For two of them (COU 850 and 1752) an arc of more than half a revolution is covered by observations; the orbits of the remaining stars have been determined from short arcs ($5^{\circ}{-}50^{\circ}…