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SDSS J080434.20+510349.2 is a WZ Sge type binary that displayed a rare outburst in 2006 (Pavlenko et al. 2007). During the long-lasting tail of the late stage of the outburst, the binary showed a two-humped or four-humped profile of the orbital light modulation. The amplitude of the orbital light curve decreased while the mean brightness decreased; moreover, that occurred ∼ 10 times faster during the fast outburst decline with respect to the late quiet state of slow outburst fading. There were no white dwarf pulsations detected in this system, neither 1 - 1.5 months prior to the outburst, nor in 1.5 - 2 months after the 2006 outburst. However, strong non-radial pulsations with period 12.6 minutes and a mean amplitude of 0.05m were first detected in the V band with the 2.6-m Shajn mirror telescope of the Crimean astrophysical observatory, ∼ 8 months after the outburst. The evolution of pulsations over two years, in 2006 - 2008, is considered. It is supposed that pulsations first appeared when the cooling white dwarf (after the outburst) entered the instability strip, although the possibility of temporary lack of pulsations at some occasions could not be excluded.

The spectral and photometric studies of the cataclysmic variable Gaia 19cwm (or ZTF19aamkwxk) have been performed. Based on the analysis of long-term variability, it is concluded that the object belongs to WZ Sge type stars. The light curves show eclipses recurring with an orbital period of min, as well as an out-of-eclipse variability with a period of min. The latter period is stable for years and appears to correspond to the rotation of a magnetic white dwarf, i.e., Gaia 19cwm is an intermediate polar. The Gaia 19cwm spectra show photospheric lines of the white dwarf, and Doppler tomograms demonstrate the presence of an accretion disk and a hot spot. Analysis of the eclipse light curve gives an estimates of the white dwarf mass , the donor mass , and the orbital inclination . Modeling of the spectral energy distribution gives the white dwarf temperature of K. The X-ray luminosity erg/s allows to assign Gaia 19cwm to a small group of low-luminosity intermediate polars.

This paper is an analysis of data from multicolor photometric observations of the asynchronous polar IGR J19552+0044 obtained over 59 nights from 2019-2022 at the Crimean Astrophysical Observatory, as well as at the Terskol Peak, Sanglokh, and Lesniki Observatories, and data from the TESS space telescope obtained on 27 days in 2022. It is shown that the maximum amplitude of the brightness oscillations at the rotation period of the white dwarf (~2 m .5-3 m ) is observed in the Ic band and is essentially close to zero in the B band. The rotation period of the white dwarf is refined to 0.05645350(14) days. A dependence of the amplitude of the brightness curve of the rotation period on the phase of the synodic period is detected.

We present the results of our optical study of the eclipsing polar Gaia23cer. We analyze the orbital brightness variability in high ( ) and low ( ) states. The system has an orbital period min and exhibits deep eclipses with a duration s. The spectra have a red cyclotron continuum with the Zeeman H absorption triplet forming in a magnetic field with a strength MG. The source of emission lines has a high radial velocity semi-amplitude ( km s ), and its eclipse lags behind the eclipse of the white dwarf. The mass and temperature K of the white dwarf have been estimated by modelling the spectral energy distribution. The eclipse duration corresponds to a donor mass and an orbital inclination . The donor temperature was estimated to be K by modelling the elliptical variability and eclipse depth.

This paper focuses on creating a solution to counter cyber threats to the local network of modern vehicles at the level of architecture, topology and communication process. The authors pay special attention to the communication process of electronic control units within the local network. A comparative analysis of different types of cyber-attacks on modern motor vehicles has been carried out, and threat and intruder models have been formulated. By means of mathematical modeling of the topology of the local network, a method for its clustering has been implemented. Methods and mechanisms for message integrity control and node authentication have been developed. The analysis of compliance of the proposed solution to the requirements of the real-time system based on the measurement of the worst-case time delay between the end network nodes has been carried out.

Photometric studies of the dwarf nova ASASSN-19fy in the “period gap” were carried out in 2020-2021 over 24 nights at the Crimean Astrophysical Observatory of the Russian Academy of Sciences and 3 nights at the Sanglokh International Astronomical Observatory of the Institute of Astrophysics, National Academy of Sciences of Tajikistan. The observations covered a superoutburst, two successive rebrightenings, and a slow return to the pre-outburst (quiescent) state. During this time, superhumps were observed, in the evolution of which the stages of developed superhumps “B,” their damping “C,” and a transition between them were identified. The average period of the superhumps in stage “B” was 0.09278(13) days and it was found its increase during this stage at a rate of (dP / dT) / P = 10·10 –5 . In stage “C” the period of the superhumps was equal to 0.092289(15) days. It is shown that ASASSN-19fy is the twelfth object to join the group of long-period dwarf novae similar to WZ Sge-type stars.

— In this paper, details of the detection of new object MASTER OT J044907.58+705812.7 (AT2024aaf) discovered on January 14, 2024 during a regular survey using the MASTER-Tunka telescope of the MASTER Global Network of Moscow State University have been present. Additional photometry of the object during joint observations at AZT-11 and 2.6-m ZTSh telescopes of CrAO RAS, MASTER-Tunka, and MASTER-Kislovodsk telescopes has been obtained. Large amplitude , blue color at maximum, brightness fluctuations during the flare with a characteristic time of ~0.06 days, long (at least 50 days) return to a calm state, the presence of at least four repeated rebrightenings gives grounds to classify the object as a dwarf nova of the WZ Sge type with multiple rebrightenings. In the paper, details of the detection of flares of other dwarf novae: MASTER OT J195416.74+494421.1, MASTER OT J150719.46–283114.9, MASTER OT J185835.32–354042.2, MASTER OT J174714.38+150048.1, and MASTER OT J065054.42+593625.5 as an example of the operation of software for processing wide-field images and identifying new and variable sources in them in real time have also been provided.

— This article presents a functional graph model of a network with adaptive topology, where the network nodes represent the graph vertices, and data exchange between the nodes is represented as edges. The dynamic nature of network interaction complicates the solution of the problem of monitoring and controlling the operation of a network with adaptive topology, which should be done in order to ensure a guaranteed correct network interaction. The importance of solving such a problem is justified by the creation of modern information and cyber-physical systems, which are based on networks with adaptive topology. The dynamic nature of links between nodes, on the one hand, makes it possible to provide self-regulation of the network and, on the other hand, significantly complicates the control over the network operation, because it is impossible to identify a single pattern of network interaction. On the basis of the developed model of the network with adaptive topology, a graph algorithm for link prediction is proposed, which is extended to the case of peer-to-peer networks. The algorithm is based on the significant parameters of network nodes characterizing both their physical characteristics (signal level and battery charge) and their characteristics as objects of network interaction (characteristics of the centrality of graph nodes). The correctness and adequacy of the developed algorithm is confirmed by the experimental results on modeling a peer-to-peer network with adaptive topology and its self-regulation when different nodes are removed.

This paper studies issues related to the implementation of intellectual synthesis of cyber-resilient structures. Methods are proposed that implement synthesis both at the stage of designing the network structure and at the stage of its recovery during a cyberattack or failure. The experimental results confirming the efficiency of the proposed methods are presented. The architecture of the system for detecting cyberattacks and intellectual synthesis of cyber-resilient network structures is described.

Results from observation campaigns for the dwarf nova NY Ser during 2014 and 2016 are presented. Data were obtained on a total of 126 nights in 2014 that include 20 normal outbursts and one superoutburst and on 22 nights in 2016 that include 5 normal outbursts. The shape of the curves for the normal outbursts indicated the existence of “outside-in” and “inside-out” outbursts in this system. In different stages of outburst activity (quiescent state, outburst, and superoutburst) NY Ser manifests brightness oscillations with different periods. In the quiescent state and in normal outbursts, the orbital period 0 d .097558(6) predominated. During the superoutburst we identified two stages in the evolution of superhumps: a stage in which the tidal instability of the accretion disk increases (A) and a stage with developed superhumps (B). Stage A for NY Ser has been identified for the first time, but its duration and period are not uniquely determined. In stage B, positive superhumps with an average period of 0 d .10464(9) and a period excess of ε = 0.072 were recorded and negative superhumps with an average period of 0 d .0938(1) and a period deficit of ε = -0.038 were detected for the first time.