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In the 21st century, in modern veterinary reproduction, the study of vaginal smear cytology is very promising. This method is simple to implement and has a relatively low cost. Its use in the clinical reproduction of dogs is of great diagnostic value, as well as in the diagnosis of gynaecological diseases. The method of vaginal cytology allows you to most accurately determine the beginning and end of the fertile period. The purpose of the work is to study the modern method of diagnosing “hidden sex activity” in a female dog and to describe a clinical case of determining the day of the oestrous cycle by the cytological method. The objectives of the research are 1) to study the cellular composition of smears of a female dog at different stages of the sexual cycle; 2) features of the estrus cycle based on changes in the picture of the cytological smear and identify the days of estrus.

Highlights. For the first time, mapping models of morbidity and mortality from the blood circulation system diseases for assessing the performance of the health protection system in federal districts of the Russian Federation were proposed. The method makes it possible to identify low-quality health systems, and outsider regions, where it is necessary to develop measures in order to identify modifiable and non-modifiable risk factors and improve the performance of health care system both in federal districts and in the Russian Federation as a whole.Aim. To develop mapping models of morbidity and mortality from the blood circulation system diseases (BCSD) and to propose indices for assessing the performance of the health care system in different federal districts of Russia over a 10-year period (from 2010 to 2019).Methods. Reporting forms of federal statistical observation in the field of public health were used.Results. The incidence of BCSD among the population of the Russian Federation has been steadily increasing over the past two decades, increasing 2.047-fold from 2000 to 2019, while the mortality rate of the Russian population decreased 2.073-fold over the same period. Mapping models of morbidity and mortality from BCSD have been developed and indices for assessing the performance of the health protection system in different federal districts of Russia over a 10-year period (from 2010 to 2019) have been proposed.Conclusion. The mapping of low and ultra-low incidence rates of BCSD combined with high and ultra-high mortality rates from BSC among the population of the federal districts indicates low detection rates and low performance of the primary health care system in detecting BSC among the population assigned to receive primary health care according to the territorial principle. The correlation of indicators of general morbidity and mortality from HIPC in relation to health care resources allows timely assessment and finding resources in those areas that contribute to the maximum efficiency of medical organizations at minimum cost.

The article demonstrates the results of a study to study the comparative assessment of the concentration of ammonia in the peripheral blood of patients with a viral infection of COVID-19 against the background of previously existing hepatic pathology and without it. There was a correlation between peripheral blood hyperammonemia and an increase in the concentration of markers of acute inflammation. The relationship between a high degree of hyperammonemia and a severe course / death as a result of the development of a new coronavirus infection in the studied patients was traced. The role of the initial chronic hepatic pathology (including non-alcoholic fatty liver disease) as a factor in the unfavorable course of the new coronavirus infection is highlighted.

The results of the study on the effect of new microbial preparations on the dynamics of the absolute weight and average daily gain of geese are presented. In the scientific experiment, probiotics Vetom 20.76 based on the predatory fungus Arthrobotrys oligospora and Vetom 1 on the basis of live spore-forming bacteria of the Bacillus subtilis DSM 32424 strain, which have anthelmintic, antiviral and antifungal effects, were used. One control and four experimental groups of 10 goslings each at the age of 1 month were formed according to the principle of analog pairs. The goslings of the experimental groups received Vetom 20.76 in various dosages: young birds of the 1st experimental group – 0.5 μl/kg of live body weight, the 2nd – 1 μl/kg, the 3rd – 2 μl/kg. Goslings of the 4th experimental group were given Vetom 1 at a dose of 50 mg/kg of live body weight. Both drugs were given in the morning with water, once a day for 30 days. These drugs were not prescribed to geese of the control group. It was established that Preparations Vetom 20.76 in doses of 0.5; 1 and 2 μl/ kg of body weight and Vetom 1 at a dose of 50 mg/kg of body weight have a growth-stimulating effect when given to goslings for 30 days. The growth rate of the experimental birds depended on the dose of the drugs used. Optimal results were obtained with the use of Vetom 20.76 at a dose of 2 μl/ kg of body weight and Vetom 1 at a dose of 50 mg/kg of body weight once a day for 30 days. The average daily gain in live weight of the experimental geese increased in the 3d and 4th experimental groups by 5.24 and 20.60% in the first 15 days of the experiment and by 24.8 and 44.64% during the aftereffect of the drug.

The effect of the probiotic preparation Vetom 1 was studied on the quantitative indicators of microflora of gastrointestinal tract of pigs of the Large White breed kept at a pig farm. Vetom 1 is a powder for oral administration and rectal administration, containing dry bacterial mass of live spore-forming bacteria of Bacillus subtilis DSM 32424 strain. Based on the analogue principle, experimental and control groups of 10 animals in each were formed. Pigs of the experimental group were given Vetom 1 at a dose of 75 mg/kg of live body weight once a day every day for 15 days. When applied, the concentration of bifidobacteria increased. Vetom 1 did not affect the dynamics of the concentration of lactobacilli, enterobacteria and fungi in the gastrointestinal tract of pigs. Under the influence of the preparation, the correlation dependences between different populations of microorganisms of the gastrointestinal tract of animals changed. Without the use of the probiotic preparation, the concentrations of lactobacilli and bifidobacteria inversely correlated with each other with an average intensity. When using Vetom 1, the populations of these microorganisms in the gastrointestinal tract of pigs were synergistic in relation to each other and showed a positive correlation dependence of the average intensity. No correlation dependences were found between concentrations of enterobacteria and other studied microorganisms. Without the use of the probiotic preparation, concentrations of bifidobacteria and fungi inversely correlated with each other with a strong intensity. When Vetom 1 was used, the populations of these microorganisms in the gastrointestinal tract of pigs did not show either synergistic or antagonistic activity among themselves, since the confidence interval of the correlation coefficient equaled zero.

—The article presents the results of multicolor photometry, medium and low resolution spectroscopy of the red nova V838 Mon remnant for 16 years after the 2002 outburst. We also used the archival photometry with the photographic plates of the Sonneberg and Moscow collections from 1928 to 1994. Analysis of these observational data confirmed that the progenitor of the V838 Mon explosion was a wide pair of B3V type stars of reduced luminosity. A brighter component exploded; it was 36 per cent brighter than its companion, and located on the zero-age main sequence of the Spectrum–Luminosity Diagram. Immediately after the outburst, in the fall of 2002, the remnant was a brown L-type supergiant (sgL), but in the fall of 2003 its spectrum changed to M type with a blue radiation excess appeared in the spectral energy distribution, which we interpreted as the reflection effect of the B type companion on the dust formed on the M star. In 2008, the companion was engulfed by the expanding explosion remnant, a type M supergiant (sgM). When the companion was immersing in the expanding M-star, a void was discovered under the M-star upper layer, in which the companion moved for about 200 days. Over the past 10 years, the luminosity of the M star has increased in the V filter by a factor of 10, and the spectral type has changed from M7.5 to M5.5. Based on radial velocities in the BaII 6497 A and CaI 6572 A lines, a deceleration of the expanding envelope of the M supergiant was detected, and in 2018, the envelope velocity approached to the heliocentric velocity of the star +71 km s−1. Quasi-periodic changes with a period of 320 days appeared then in the light curves, especially clearly expressed in I filter. We assume that the remnant has an elongated structure, and its rotation period is about 640 days. This is probably a gigantic contact system that will become a detached binary system in future development. The observations do not confirm the assumption that the explosion of one of the V838 Mon components was due to the merger of a compact binary system components located in a hierarchical triple one. Two hypotheses were proposed on the nature of the explosion of one of the V838 Mon components, directly based on the early age of this system: (1) the ignition of thermonuclear burning of hydrogen in the core after the gravitational compression of a protostar; (2) the fragmentation of the core inside a rapidly rotating star in the stage of gravitational compression of a protostar, and later, the subsequent defragmentation (merger of the core components) due to the loss of torque.

A tissue culture method has been used for the breeding of buckwheat (Fagopyrum esculentum Moench) in the presence of high concentrations of heavy metal ions in a nutrient medium as selective factors. Based on the Izumrud (Russia) and Kitawase (Japan) varieties and their hybrid (Izumrud × Kitawase), some copper- and zinc-tolerant regenerant lines have been derived. The negative effect of copper ions in the form of chlorophyll mutants has been observed starting from the second generation of regenerant plants. A positive effect of heavy metals on the increase of a rutin content in regenerants has been observed under in vitro conditions. The field evaluation of heavy metal-tolerant samples has allowed us to select lines highly adapted to the monsoon climate of Primorsky krai and to combine such features as large grain size (thousand kernel weight is equal to 36–38 g), high seed productivity (1.9–3.2 g), and high rutin content in green mass (2.8–4.3%).

The article presents results of usage of the tissue culture method on buckwheat (Fagopyrum esculentum Moench) together with the selective factor increased concentrations of heavy metal ions in the nutrient medium. On the basis of Izumrud (Russia), Kitavase (Japan), hybrid Izumrud x Kitavase there were developed regenerant lines tolerant to copper and zinc. Negative action effect of copper ions was observed from the second generation in the second posterity of the plants-regenerants, developed from the callus, in the form of the chlorophyll-free mutants. Positive effect of the heavy metals was observed on increasing of rutin content of the plants-regenerants in vitro. Selective evaluation in the field conditions of the samples tolerant to heavy metal let to choose from them the most adaptive to monsoon conditions in Primorskykrai, which combine valuable traits of big grain (weight of 1000 grains 36-38 g), high seed productivity (1,9-3,2 g) and high rutin content in aboveground mass of plants (2,8-4,3 %).

We present an observational study of the luminous red nova (LRN) AT 2021biy in the nearby galaxy NGC 4631. The field of the object was routinely imaged during the pre-eruptive stage by synoptic surveys, but the transient was detected only at a few epochs from ∼231 days before maximum brightness. The LRN outburst was monitored with unprecedented cadence both photometrically and spectroscopically. AT 2021biy shows a short-duration blue peak, with a bolometric luminosity of ∼1.6 × 1041 erg s−1, followed by the longest plateau among LRNe to date, with a duration of 210 days. A late-time hump in the light curve was also observed, possibly produced by a shell-shell collision. AT 2021biy exhibits the typical spectral evolution of LRNe. Early-time spectra are characterised by a blue continuum and prominent H emission lines. Then, the continuum becomes redder, resembling that of a K-type star with a forest of metal absorption lines during the plateau phase. Finally, late-time spectra show a very red continuum (TBB ≈ 2050 K) with molecular features (e.g., TiO) resembling those of M-type stars. Spectropolarimetric analysis indicates that AT 2021biy has local dust properties similar to those of V838 Mon in the Milky Way Galaxy. Inspection of archival Hubble Space Telescope data taken on 2003 August 3 reveals a ∼20 M⊙ progenitor candidate with log (L/L⊙) = 5.0 dex and Teff = 5900 K at solar metallicity. The above luminosity and colour match those of a luminous yellow supergiant. Most likely, this source is a close binary, with a 17–24 M⊙ primary component.

The influence of the climate change on the agro-climatic growth conditions, development and formation of productivity of meadow and steppe vegetation in the forest-steppe zone of Ukraine for three periods has been studied: 2021–2030, 2031–2040, 2041–2050. The calculations of the expected conditions have been performed according to the climate change scenarios RCP4.5 and RCP8.5. The paper provides an assessment of the agro-climatic conditions for the formation of productivity of meadow and steppe vegetation in the current global warming and further climate change conditions until 2050. The assessment has been performed by comparing the average long-term agro-climatic indicators (1980–2010) of the productivity of wild phytocenoses with the same indicators for the future over decades. The calculations of both average long-term productivity of grasses and productivity of grasses in the conditions of climate change are executed according to four types of productivity: potential productivity which in case of optimum maintenance of plants with heat, moisture and mineral food is defined by solar radiation; meteorologically possible yield, which is provided by the temperature regime and the regime of humidification of the territory; really possible yield capacity, which is provided by the natural fertility of the soil; actual yield capacity in the natural conditions. Key words: meadow, steppe vegetation, productivity, humus balance, photosynthetic potential, agroecological categories of yields, climate change.

The physicomechanical properties of zirconia-based thermal barrier coatings, which are deposited by air-plasma method on a heat-resistant VKh4A high-chromium nickel alloy and are subjected to heat treatment under various conditions imitating real exploitation processes of the coatings, are studied. To estimate the fracture strength of the coatings (critical stress intensity factor K1c) and Young’s modulus, Vickers microindentation is used. This method is shown to allow one to estimate the effect of a heat load and to find the factors affecting the properties of the coatings.

The paper explores the effect of heterolytics on the basis of apathogenic bacilli Vetom 1 and Vetom 1.23 when applying by means of different ways on quantitative and qualitative parameters of white blood cells of lactating cows. The researchers arranged 4 experimental groups and a control one. Animals of the 1st and 2nd experimental groups received a microbial specimen Vetom 1 dosed 50 and 12.5 mg / kg of body weight, respectively, once a day during 30 days. Animals of the 3rd and 4th experimental groups received microbial preparation Vetom 1.23 dosed 1.0 and 0.5 µl / kg of body weight, respectively, once a day during 30 days. The cows from the control group didn’t receive the specimens. The experiment resulted in the fact that investigated specimens are physiologic for animal organisms and changes in leukocytes and their fractions occur with the same regularity and within the physiological norm. During application of Vetom 1 and Vetom 1.23 the number of leukocytes, monocytes and granulocytes was increased, and the number of lymphocytes decreased. Upon termination of specimen application, the authors found out higher level of leukocytes, monocytes and granulocytes on the 60th day of research, whereas the number of lymphocytes when using Vetom 1 dosed 50 mg/kg of weight at the level of analogues from the control, and in animals of other experimental groups – decreases. The severity of changes in the studied components depended on the specimen used and the dose of it. Maximum increase in white blood cells, monocytes and granulocytes either in the period of specimen application, and after it was observed during application of Vetom 1 dosed 50 mg/kg. Granulocytic immunity is modulated by application of Vetom 1

We analyzed a 40-year set of multicolor photometry and a 15-year set of synoptic monitoring of SS 433 along with fragmentary spectral and radio data. This system contains a neutron star and an A3–A7 I giant. The system is found to be either close, in contact, or it has a common envelope from time to time. The A-type giant is now in transition to the dynamical mass transfer.

Article in question investigates indicators of the moisture-temperature regime for the period of 1986 - 2005 (base period) and compares them to their expected changes calculated for different scenarios of climate change GFDL-30 %, A1B, A2, RCP4,5 and RCP8,5 for the period of 2021 - 2050 on the territory of Ukraine. Calculations reviled that most abrupt changes in moisture-temperature indicators in different soil-climatic zones of Ukraine can be expected in case of scenarios GFDL-30 %, А1В and А2. In case of scenarios of climate change RСР4,5, RСР8,5 thermal indicators are expected to be at the level of multilevel averages in all natural and climatic zones of Ukraine, except for Southern Steppe, where they are expected to grow. The greatest changes in all areas are expected under scenario GFDL-30 %, and they will increase from north to south. Under scenario А1В the greatest difference between calculated values and average multi-year values will be observed in the Forest-Steppe zone and in the Southern Steppe. Under scenarios RCP4,5 и RCP8,5 significant changes in the temperature regime are predicted only for the south and east of Ukraine. At the same time, according to the scenario of RCP4.5, a significant increase in seasonal winter air temperatures is forecasted. Analysis of the results of calculations for different climatic scenarios of water availability indicators for different natural and climatic zones of Ukraine for the period from 2021 to 2050 reviled that the most drastic changes in the climatic parameters of humidification are expected in the case of the scenarios GFDL-30 %, A1B and A2. In case of climate change scenarios RCP4.5, RCP8.5, no quick changes in the distribution of precipitation over the territory of Ukraine should be ex-pected. The greatest amount of precipitation for the year and in average for the seasons of the year is projected for the western regions of the country, the least one - for the southern regions. At the same time, for most regions the trend to increase the amount of precipitation is most likely in the case of the development of the GFDL-30 %, A1B and A2 scenarios. However, according to the scenarios RCP4.5 and RCP8.5, rainfall is expected to decline for the year as a whole and especially in the summer season in comparison with the actual for 1986 - 2005.

We present spectroscopy and multicolor photometry for the optical transient PSN J09093496+3307204 in the galaxy NGC2770, which has afterwards been transferred into the supernova phase and got the name SN2015bh. Medium-resolution spectral observations were carried out between February 2015 to May 2016 using the focal reducer SCORPIO at the 6-m Russian telescope BTA. They were followed by by photometric observations at the BTA and six other telescopes with 0.5–1m apertures. Both at the phase of the SN impostor (2015a) and at the supernova phase (2015b), besides Balmer emissions, the strong Fe II emissions are seen in the spectrum; so, these spectra resemble those of Williams Fe II type classical novae. Taking into account circumstellar, interstellar and galactic absorption, AV = 1.m 14 ±0.m 15), we determined maximum absolute magnitudes of the object to be MV =–15.m 0 ±0.m 3 at the 2015a phase and of MV =–18.m 14 ±0.m 30 at the 2015b phase. The light curve at the 2015b phase is similar to those of SN IIL. The supernova progenitor is a luminous blue variable (LBV) star with the powerful Hα emission. We consider several hypotheses of supernovae explosions following optical transients related with LBV. The hypothesis of core collapse of an evolved massive star interrupting the process of its merging with massive companion in a binary system (a failed luminous red nova) was chosen as the preferable one for this event.

We present the results of the study of the red nova PSN J14021678+5426205 based on the observations carried out with the Russian 6-m telescope (BTA) along with other telescopes of SAO RAS and SAI MSU. To investigate the nova progenitor, we used the data from the Digital Sky Survey and amateur photos available on the internet. In the period between April 1993 and July 2014, the brightness of the progenitor gradually increased by 2.2 mag in the V band. At the peak of the first outburst in mid-November of 2014, the star reached an absolute visual magnitude of -12.75 mag but was discovered later, in February 2015, in a repeated outburst at the absolute magnitude of -11.65 mag. The amplitude of the outburst was minimum among the red novae, only 5.6 mag in the V band. The H alpha emission line and the continuum of a cool supergiant with a gradually decreasing surface temperature were observed in the spectra. Such process is typical for red novae, although the object under study showed extreme parameters: maximum luminosity, maximum outburst duration, minimum outburst amplitude, unusual shape of the light curve. This event is interpreted as a massive OB star system components merging accompanied by the formation of a common envelope and then the expansion of this envelope with minimal energy losses.

We obtained a spectrum and UBVRI photometry of the star associated with the X-ray source 1RXS J051439.2-021615 that experienced a rapid optical flare on 25 January 2018 (ATel No. 11250). We classified the spectrum as K2V K5V. The Halpha line was filled with emission. We explain this event as a flare in an active region on the surface of a late-type main sequence star.

We have monitored the return to quiescence of novae previously observed in outburst as supersoft X-ray sources, with optical photometry of the intermediate polar (IP) V4743 Sgr and candidate IP V2491 Cyg, and optical spectroscopy of these two and seven other systems. Our sample includes classical and recurrent novae, short period (few hours), intermediate period (1-2 days) and long period (symbiotic) binaries. The light curves of V4743 Sgr and V2491 Cyg present clear periodic modulations. For V4743 Sgr, the modulation occurs with the beat of the rotational and orbital periods. If the period measured for V2491 Cyg is also the beat of these two periods, the orbital one should be almost 17 hours. The recurrent nova T Pyx already shows fragmentation of the nebular shell less than 3 years after the outburst. While this nova still had strong [OIII] at this post-outburst epoch, these lines had already faded after 3 to 7 years in all the others. We did not find any difference in the ratio of equivalent widths of high ionization/excitation lines to that of the Hbeta line in novae with short and long orbital period, indicating that irradiation does not trigger high mass transfer rate from secondaries with small orbital separation. An important difference between the spectra of RS Oph and V3890 Sgr and those of many symbiotic persistent supersoft sources is the absence of forbidden coronal lines. With the X-rays turn-off, we interpret this as an indication that mass transfer in symbiotics recurrent novae is intermittent., Comment: In press in Monthly Notices of the Royal Astronomical Society

We study the newly discovered variable star GSC 4560--02157. CCD photometry was performed in 2013--2014, and a spectrum was obtained with the 6-m telescope in June, 2014. GSC 4560--02157 is demonstrated to be a short-period (P=0.265359d) eclipsing variable star. All its flat-bottom primary minima are approximately at the same brightness level, while the star's out-of-eclipse brightness and brightness at secondary minimum varies considerably (by up to 0.6m) from cycle to cycle. Besides, there are short-term (time scale of 0.03-0.04 days) small-amplitude brightness variations out of eclipse. This behavior suggests cataclysmic nature of the star, confirmed with a spectrum taken on June 5, 2014. The spectrum shows numerous emissions of the hydrogen Balmer series, HeI, HeII., 38 pages, 6 figures

We present the multicolor BV RI photometry and BTA/SCORPIO spectroscopy for the red nova V4332 Sgr, performed in 2005–2012. We have analyzed the behavior of the nova remnant, considering our observations along with all the published observations and archival photographic photometry. The atomic and molecular emission spectra show an exponential weakening. Since 2003, the line fluxes have on the average decreased 30-fold. The continuum of the M-type giant in the spectrum has weakened abruptly between 2006 and 2008, twice in the red and by 4 times in the blue range. The variations in the spectral energy distribution of the stellar continuum after the outburst correspond to a decrease in the surface temperature of the M-type giant by 1000 K. The presence of a faint star of about 20m is possible. The star can be either a member of the system or a field star. It is found that the phenomenon of the red nova in this system is not related with the M-type star. The progenitor of the explosion could be a blue straggler, which has disappeared from the spectral energy distribution after the explosion of 1994. It is most likely that this object was a contact binary system. To explain the “cold explosion” of V4332 Sgr, we have accepted the hypothesis of merging components of a contact binary star in a hierarchical triple or multiple system. There are evidences of dynamical destruction of the outburst remnant and accretion of its matter to the M-type giant. The cause of the red nova phenomenon is thought to be a sudden explosive energy release in the center of a star having a massive envelope, and a subsequent expansion of the envelope in the conditions close to adiabatic. As a result of the explosion, thermal energy reaches the surface of the envelope a year or a few years after the outburst, whereas the envelope already has a large surface area. The cause of the explosion in the center of the star can be both a merger event of the nuclei of two stars in the contact system with a formed common massive envelope and instability in the core of a single massive star. Thus, the red novae can be heterogeneous objects at different evolutionary stages.

The Andromeda Galaxy recurrent nova M31N 2008-12a had been observed in eruption ten times, including yearly eruptions from 2008-2014. With a measured recurrence period of $P_\mathrm{rec}=351\pm13$ days (we believe the true value to be half of this) and a white dwarf very close to the Chandrasekhar limit, M31N 2008-12a has become the leading pre-explosion supernova type Ia progenitor candidate. Following multi-wavelength follow-up observations of the 2013 and 2014 eruptions, we initiated a campaign to ensure early detection of the predicted 2015 eruption, which triggered ambitious ground and space-based follow-up programs. In this paper we present the 2015 detection; visible to near-infrared photometry and visible spectroscopy; and ultraviolet and X-ray observations from the Swift observatory. The LCOGT 2m (Hawaii) discovered the 2015 eruption, estimated to have commenced at Aug. $28.28\pm0.12$ UT. The 2013-2015 eruptions are remarkably similar at all wavelengths. New early spectroscopic observations reveal short-lived emission from material with velocities $\sim13000$ km s$^{-1}$, possibly collimated outflows. Photometric and spectroscopic observations of the eruption provide strong evidence supporting a red giant donor. An apparently stochastic variability during the early super-soft X-ray phase was comparable in amplitude and duration to past eruptions, but the 2013 and 2015 eruptions show evidence of a brief flux dip during this phase. The multi-eruption Swift/XRT spectra show tentative evidence of high-ionization emission lines above a high-temperature continuum. Following Henze et al. (2015a), the updated recurrence period based on all known eruptions is $P_\mathrm{rec}=174\pm10$ d, and we expect the next eruption of M31N 2008-12a to occur around mid-Sep. 2016., 46 pages, 19 figures, 14 tables, accepted for publication in ApJ (accepted version, minor changes made during the refereeing process)

We report photometric and spectroscopic observations of the optical transient LSQ13zm. Historical data reveal the presence of an eruptive episode (that we label as `2013a') followed by a much brighter outburst (`2013b') three weeks later, that we argue to be the genuine supernova explosion. This sequence of events closely resemble those observed for SN2010mc and (in 2012) SN2009ip. The absolute magnitude reached by LSQ13zm during 2013a ($M_R=-14.87\pm0.25\,\rm{mag}$) is comparable with those of supernova impostors, while that of the 2013b event ($M_R=-18.46\pm0.21\,\rm{mag}$) is consistent with those of interacting supernovae. Our spectra reveal the presence of a dense and structured circumstellar medium, probably produced through numerous pre-supernova mass-loss events. In addition, we find evidence for high-velocity ejecta, with a fraction of gas expelled at more than 20000\kms. The spectra of LSQ13zm show remarkable similarity with those of well-studied core-collapse supernovae. From the analysis of the available photometric and spectroscopic data, we conclude that we first observed the last event of an eruptive sequence from a massive star, likely a Luminous Blue Variable, which a short time later exploded as a core-collapse supernova. The detailed analysis of archival images suggest that the host galaxy is a star-forming Blue Dwarf Compact Galaxy., Comment: Accepted for publication on MNRAS

ZnSe1 − xSx (1 ≥ x ≥ 0) crystals are grown from the vapor of binary components in a closed horizontal system. The ZnSe1 − xSx crystals doped with chromium and cobalt are prepared by post-growth diffusion. Their absorption spectra are studied depending on the composition of the solid solution and the doping level. The diffusion coefficients of chromium and cobalt at the temperature 1040°C and their dependence on composition are determined.

V934 Her is a detached system, consisting of a cool giant and a neutron star. The neutron star accretes matter fromthe stellarwind of the giant.Multicolor photoelectric observationsmade in 1997–2011 revealed a 415-day period, close to that, discovered spectroscopically from radial velocities. This period is considered to be the orbital period of orbital motion of the neutron star around the red giant. The wave with this period in the U-band has the largest amplitude 0m.12. We also detected multiperiodic pulsations of the red giant. The light curve in the V -band is dominated by a pulsation wave with the period of 28.82 days and the amplitude of 0m.10.

A technique of evaluating the micromechanical characteristics (namely, microhardness, microdurability, microbrittleness and static crack resistance coefficient) using microindentation as applied to plasma zirconia-based thermal barrier coatings is presented.

We present photometry and moderate-resolution spectroscopy of the luminous red variable [HBS2006] 40671 originally detected as a possible nova in the galaxy M33. We found that the star is a pulsating Mira-type variable with a long period of 665 days and an amplitude exceeding 7 mag in the R band. [HBS2006] 40671 is the first confirmed Mira-type star in M33. It is one of the most luminous Mira-type variables. In the K band its mean absolute magnitude is M_K = -9.5, its bolometric magnitude measured in the maximum light is also extreme, M_bol = -7.4. The spectral type of the star in the maximum is M2e - M3e. The heliocentric radial velocity of the star is -475 km/s. There is a big negative excess (-210~km/s) in radial velocity of [HBS2006] 40671 relative to the average radial velocity of stars in its neighborhood pointing at an exceptional peculiar motion of the star. All the extreme properties of the new Mira star make it important for further studies.

Partially faceted ZnSe1 − xSx solid solution crystals have been grown from a vapor phase in a closed stationary horizontal system. The growth has been performed in cylindrical quartz ampoules—∼10 mm in diameter and evacuated to a residual pressure of less than ∼10−3 Pa-at a temperature of 1050°C and a temperature drop between the source and growth zones of 10–16°C. The crystal structure, optical absorption, and composition inhomogeneity along the ingot length have been investigated by X-ray diffractometry and optical spectroscopy in the wavelength range of 300–3000 nm. The solid-solution composition range corresponding to cubic polymorphs is determined. The concentration dependences of the lattice parameter and band gap are presented.

CI Cam is a well-known B[e]-type star and an X-ray transient, which underwent a powerful outburst in all parts of electromagnetic spectrum in 1998. An extensive V-band photometric monitoring revealed that rapid variability of CI Cam on the time scale of several hours is due to the pulsations of the B4 III–V type component. High-precision CCD photometry of the star was performed with the 50-cm Maksutov (meniscus) telescope of the Crimean station of the Sternberg Astronomical Institute of Moscow State University in December 2006 during the quiescent state of the star. The data are analyzed using the methods of discrete Fourier transform and by modeling of the light curve. The amplitude spectrum of the star is dominated by two peaks corresponding to the periods of 0.41521 and 0.26647 days with the period ratio close to 3:2. At least two pulsation modes are excited and the star exhibits signs of the resonance between modes.

We report an 11-year long series of U BV RI observations and the results of our monitoring of the classical slow nova V723 Cas. We analyze the spectra of this star taken using the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences with a spectral resolution of 3.5–8.5 A during the nebular stage and at the supersoft X-ray source phase (SSS). This systemhas a large orbital inclination and its orbital period is equal to 0.693265 days. The orbital period increases. We found low-amplitude light variations with the orbital period during the early stages of the outburst and even at the pre-maximum stage. The orbital light curve at the nebular stage is asymmetric and gradually increases its amplitude up to V=2 m in 2006. The asymmetry of the light curve of V723 Cas can be explained by the reflection effect, eclipse of the extended accretion disk, and high rate of mass transfer in the system. The light curve of V723 Cas has developed a plateau due to the SSS phase. In the spectrum of V723 Cas the transition to the SSS phase shows up in an order-of-magnitude increase of the flux of the [Fe X] λ 6374 A emission, which forms in the expanding envelope. In addition, narrow emission lines λ 6466.4 A (O V) and λ 6500.5 A (Fe XVII) also emerged in the spectrum.

M31N 2015-01a (or M31LRN 2015) is a red nova that erupted in January 2015 -- the first event of this kind observed in M31 since 1988. Very few similar events have been confirmed as of 2015. Most of them are considered to be products of stellar mergers. Results of an extensive optical monitoring of the transient in the period January-March 2015 are presented. Eight optical telescopes were used for imaging. Spectra were obtained on BTA, GTC and the Rozhen 2m telescope. We present a highly accurate 70 d lightcurve and astrometry with a 0.05" uncertainty. The color indices reached a minimum 2-3 d before peak brightness and rapidly increased afterwards. The spectral type changed from F5I to F0I in 6 d before the maximum and then to K3I in the next 30 d. The luminosity of the transient was estimated to $8.7^{+3.3}_{-2.2}\times10^{5}L_{\odot}$ during the optical maximum. Both the photometric and the spectroscopic results confirm that the object is a red nova, similar to V838 Monocerotis., 5 pages, 4 figures, 4 tables, accepted for publication in Astronomy and Astrophysics as a Letter to the Editor; page 5 is online material only

Our long-time monitoring of the B[e] star and transient X-ray source CI Cam during quiescence following the 1998 outburst demonstrates that the complex, stratified circumstellar envelope has tended to stabilize after this structure was perturbed by the passage of a shock wave from the outburst. The star’s U BV R brightness shows slow, possibly cyclic, variations with an amplitude of about 0.2m. We determined the spectral type of the primary, B4III-V, based on the widths of the absorption wings of high-numbered Balmer lines. A Doppler shift of 460 km/s was detected for the Hell λ4686 A emission line. The shifts in this line yield an orbital period of 19.41 days, which is also manifested itself in the photometric data as a wave with a V amplitude of 0.034m. The orbit is elliptical, with an eccentricity of 0.62. It is most likely that the secondary is a white dwarf surrounded by an accretion disk. The primary’s mass exceeds 12 M ⊙ . The system may be at a late stage of its evolution, after the stage of mass exchange.

Results of simultaneous INTEGRAL and optical observations of galactic microquasar SS433 in May 2003 and INTEGRAL/RXTE observations in March 2004 are presented. Persistent precessional variability with a maximum to minimum uneclipsed hard X-ray flux ratio of \sim 4 is discovered. The 18-60 keV X-ray eclipse is found to be in phase with optical and near infrared eclipses. The orbital eclipse observed by INTEGRAL in May 2003 is at least two times deeper and apparently wider than in soft X-ray band. The broadband X-ray spectrum 2-100 keV simultaneously detected by RXTE/INTEGRAL in March 2004 can be described by bremsstrahlung emission from optically thin thermal plasma with kT\sim 30 keV. The optical spectroscopy with the 6-m SAO BTA telescope confirmed the optical companion to be an A5-A7 supergiant. For the first time, spectorscopic indications of a strong heating effect in the optical star atmosphere are found. The measurements of absorption lines which are presumably formed in the non-illuminated side of the supergiant yield its radial velocity semi-amplitude K_v=132\pm 9 km/s. The analysis of the observed hard X-ray light curve and the eclipse duration, combined with spectroscopically found optical star radial velocity corrected for the strong heating effect, allows us to model SS433 as a massive X-ray binary. Assuming that the hard X-ray source in SS433 is eclipsed by the donor star that exactly fills its Roche lobe, the masses of the optical and compact components in SS433 are suggested to be M_v\approx 30 M_\odot and M_x\approx 9M_\odot, respectively. This provides further evidence that SS433 is a massive binary system with supercritical accretion onto a black hole., 15 pages, AA style, 17 figures, accepted for publication in AA; replaced to match the accepted version

We present the results of our CCD photometric and moderate-dispersion spectroscopic observations of the binary system V4641 Sgr, which contains a black hole of mass ≈9.5M⊙ and a normal B9III star. The photometric light curve reveals an ellipticity effect with very high amplitudes in V and R, 0.40m and 0.37m, and the color curve shows that the surface temperature is nonuniform. All this testifies to tidal distortion of the normal star's surface due to the massive companion and to a high inclination of the orbit to the line of sight. In June and July 2002, during quiescence, we obtained data during three flares with amplitudes up to 0.26m. In particular, spectroscopic observations were acquired near the time of the black hole's inferior conjunction. One hour before conjunction, a depression by EW=0.5 A was observed in the red wing of the Hα absorption line, interpreted as absorption by gas flowing in the direction from the observer toward the normal star. This flow is apparently associated with a rarefied gas disk around the black hole, and the conjunction grazes the stellar surface if the orbital inclination is close to 70.7°. The maximum velocity along a circular Keplerian orbit is 650 km/s at a distance of R=0.15–0.20a from the black hole (where a is the component separation). Thus, we find the mass of the black hole to be MBH=7.1–9.5M⊙, confirming the model of Orosz et al. (2001).

The photometric monitoring of Nova V 1494 Aql at the Sternberg Astronomical Institute and at the Special Astrophysical Observatory in July and September 2002 has confirmed that the star is an eclipsing system. Its orbital period was improved, $$0\mathop .\limits^d 1346141(5)$$ . Light elements and eight mid-eclipse times are given. The light-curve shape suggests that the star is an intermediate polar.

We obtained U BV R photometric and spectroscopic observations during the outburst of V838 Mon. Before its outburst, the B brightness of the star had been stable ( $$\tilde15.^m 85$$ ) for 45 years. This was a blue star with the color index $$(B - V)_0 = - 0\mathop .\limits^m 03 \pm 0\mathop .\limits^m 1$$ and may have been a cataclysmic variable. In the middle of March 2002, the outburst amplitude reached $$8\mathop .\limits^m 1$$ in B. The star has the counterpart V 1006/7 in M 31 in luminosity at maximum and in spectrum. The unusual spectrum at the premaximum stage originated in the expanding photosphere of a cool K-type giant. The expansion velocity of the photosphere was 150 km s−1; the maximum velocity in the expanding stellar envelope reached 500 km s−1. The absorption components of neutral metal lines were enhanced by a factor of 3 or 4 compared to a normal K-type star. No overabundance of s-process elements was found. One day before the brightness peak, an intense Hα emission line with broad wings, FWZI=3100 km s−1, and numerous lines of ionized metals appeared in V838 Mon, which is characteristic of normal classical novae. We show light, color, and spectral variations of the object.

We compare U BV R photometry of CI Cam obtained using facilities at the Sternberg Astronomical Institute in 1998–2001 and medium-resolution spectroscopy obtained at the Special Astrophysical Observatory in the same period. The photometric measurements and fluxes in the Balmer and some Fe II emission lines in the post-outburst quiescent spectrum of CI Cam display cyclic variations with a period of 1100±50d. These variations could be due to orbital motion in a widely separated binary; one component, a giant, produces a reflection effect on the surface facing the other, compact component. Our V-band photometry confirms the $$11\mathop d\limits_. 7$$ period found by Miroshnichenko before the outburst but shows a lower amplitude (3%). We investigate the possibility that this photometric period is the same as the rotational period of the radio jets measured using the VLA. Based on modeling of the radio map, we estimate the inclination of the jet rotation axis to the line of sight, i=35°–40°; the angle between the rotational axis and jet ejection direction, ϑ=7°–10°; and the jet spatial velocity, 0.23–0.26 c. The equivalent widths and fluxes of various spectral lines show different variation amplitudes during outburst and significantly different behavior during quiescence. We have detected five patterns of behavior, which provide evidence for stratification of the gas and dust envelope surrounding the system. The brightening of the [N II] forbidden line is delayed by 50–250d relative to the X-ray outburst maximum.