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The problem of interpretation of a photometric light curve and the use of the Lomb–Scargle periodogram to determine the rotation period of fast-rotating artificial Earth satellites (AESs) when they are observed with a slow read-out CCD camera are described. A method for solving this problem is given. It is proposed, if there is a priori information about the AES rotation period, to use the Lomb–Scargle periodogram in a narrowed frequency range; in the absence of a priori information, the problem is solved by using trail photometry. Comparison of results obtained with different telescopes equipped with different slow read-out CCD cameras with results independently obtained with other telescopes equipped with fast read-out CCD cameras clearly demonstrates the effectiveness of the method in both cases. The limitations in the applicability of the method application and possible ways to improve its accuracy are also considered.

Clear-cut logging currently is a key factor transforming forest communities in many boreal regions. The dynamics of biogeochemical processes taking place in clear-cuts makes them a good model for studying the response of plants to changes in environmental conditions. This study aimed to assess the response of nutrient, carbon and water exchange parameters in coniferous and deciduous plants after clear-cut forest harvesting. The effects of environmental factors on the functional traits of regrowing trees in Scots pine (Pinus sylvestris L.), silver birch (Betula pendula Roth), aspen (Populus tremula L.) and grey alder (Alnus incana (L.) Moench) were analysed during four growing seasons (2016–2019) in a clear-cut site and under the canopy of an undisturbed bilberry-type pine forest in the middle taiga of Karelia, Northwest Russia. Unidirectional changes were observed in the specific nutrient content, specific leaf area, biological macronutrient absorption capacity, stomatal conductance, and rates of photosynthesis and transpiration in the different tree species along a gradient of environmental factors. In most cases, the nutrient concentrations and N:P:K ratio were consistent in all species as environmental conditions changed. Species-specific responses were observed for the N:P:K and K:Ca:Mg ratios, photosynthetic water use and nitrogen use efficiency. Contrasting environmental conditions in the clear-cut and under forest canopy most significantly affect plant capacity to absorb nitrogen. Variation in functional traits in the coniferous and deciduous species reflects their specific resource-use strategies in a heterogeneous environment and, hence, indicates the different adaptation potentials for various plant species.

We describe results of a planetary defense exercise conducted during the close approach to Earth by the near-Earth asteroid (99942) Apophis during 2020 December–2021 March. The planetary defense community has been conducting observational campaigns since 2017 to test the operational readiness of the global planetary defense capabilities. These community-led global exercises were carried out with the support of NASA’s Planetary Defense Coordination Office and the International Asteroid Warning Network. The Apophis campaign is the third in our series of planetary defense exercises. The goal of this campaign was to recover, track, and characterize Apophis as a potential impactor to exercise the planetary defense system including observations, hypothetical risk assessment and risk prediction, and hazard communication. Based on the campaign results, we present lessons learned about our ability to observe and model a potential impactor. Data products derived from astrometric observations were available for inclusion in our risk assessment model almost immediately, allowing real-time updates to the impact probability calculation and possible impact locations. An early NEOWISE diameter measurement provided a significant improvement in the uncertainty on the range of hypothetical impact outcomes. The availability of different characterization methods such as photometry, spectroscopy, and radar provided robustness to our ability to assess the potential impact risk.

The effect of site preparation (mixed mounding and removal of the humus layer) under a shelterwood of mixed boreal forest along a forest interior-edge gradient on Norway spruce (Picea abies) seedli...

In the present paper, the results of the research of biometric parameters and functional peculiarities of photosynthetic apparatus of Stellaria humifusa in West Spitsbergen are discussed. The study showed that the largest proportion of the mat is composed of a brown layer of dead leaves covering the assimilative organs (about 70%). Green leaves and shoots accounted for about 20%, whereas generative organs – for about 10% of the mat mass. The values of the maximum photochemical quantum yield of PS II (F V /F M ) in all the studied plants were lower than the optimal values (0.83), which suggests that the plants are exposed to stress factors. The low values of chlorophyll and carotenoid content and relatively high values of the light-harvesting complex (70-80%), the sharp decrease in the quantum yield of PS II ( F PSII ) entailed by a marginal increase in PPFD indicative of a sufficiently high of photochemical activity within the range of low and medium values of light. It also suggests that Stellaria humifusa is well-adapted to the shaded conditions created in the mat. Besides, a considerable decrease the maximum fluorescence yield of a light-adapted leaf (F M ´) at increasing PPFD was observed, which suggests that Stellaria humifusa has a well-developed mechanism of energy dissipation via the non-photochemical (NPQ) pathway. The rapid development of NPQ gives reason to assume that, under high light conditions, non-photochemical quenching is likely to serve as the main mechanism for preventing the photodamage of the photosynthetic apparatus. Thus, it was shown that the photosynthetic apparatus of Stellaria humifusa works efficiently under the conditions created in the mat, and the thick layer of dead leaves covering the assimilative organs, on the one hand, protects them from excessive light, and on the other hand, absorbs thermal energy, which raises temperature of the local habitat.

We present new photometric observations for twelve asteroids ((122) Gerda, (152) Atala, (260) Huberta, (665) Sabine, (692) Hippodamia, (723) Hammonia, (745) Mauritia, (768) Struveana, (863) Benkoela, (1113) Katja, (1175) Margo, (2057) Rosemary) from the outer part of the main belt aimed to obtain the magnitude-phase curves and to verify geometric albedo and taxonomic class based on their magnitude-phase behaviors. The measured magnitude-phase relations confirm previously determined composition types of (260) Huberta (C-type), (692) Hippodamia (S-type) and (1175) Margo (S-type). Asteroids (665) Sabine and (768) Struveana previously classified as X-type show phase-curve behavior typical for moderate-albedo asteroids and may belong to the M-type. The phase-curve of (723) Hammonia is typical for the S-type which contradicts the previously determined C-type. We confirmed the moderate-albedo of asteroids (122) Gerda and (152) Atala, but their phase-curves are different from typical for the S-type and may indicate more rare compositional types. Based on magnitude-phase behaviors and V-R colors, (2057) Rosemary most probably belongs to M-type, while asteroids (745) Mauritia and (1113) Katja belong to S-complex. The phase curve of the A-type asteroid (863) Benkoela does not cover the opposition effect range and further observations are needed to understand typical features of the phase-curves of A-type asteroids in comparison with other types. We have also determined lightcurve amplitudes of the observed asteroids and obtained new or improved values of the rotation periods for most of them., Comment: 16 pages

Context. The rotation state of small asteroids is affected by the Yarkovsky–O’Keefe–Radzievskii–Paddack (YORP) effect, which is a net torque caused by solar radiation directly reflected and thermally reemitted from the surface. Due to this effect, the rotation period slowly changes, which can be most easily measured in light curves because the shift in the rotation phase accumulates over time quadratically. Aims. By new photometric observations of selected near-Earth asteroids, we want to enlarge the sample of asteroids with a detected YORP effect. Methods. We collected archived light curves and carried out new photometric observations for asteroids (10115) 1992 SK, (1620) Geographos, and (1685) Toro. We applied the method of light curve inversion to fit observations with a convex shape model. The YORP effect was modeled as a linear change of the rotation frequency υ ≡ dω∕dt and optimized together with other spin and shape parameters. Results. We detected the acceleration υ = (8.3 ± 0.6) × 10−8 rad d−2 of the rotation for asteroid (10115) 1992 SK. This observed value agrees well with the theoretical value of YORP-induced spin-up computed for our shape and spin model. For (1685) Toro, we obtained υ = (3.3 ± 0.3) × 10−9 rad d−2, which confirms an earlier tentative YORP detection. For (1620) Geographos, we confirmed the previously detected YORP acceleration and derived an updated value of υ with a smaller uncertainty. We also included the effect of solar precession into our inversion algorithm, and we show that there are hints of this effect in Geographos’ data. Conclusions. The detected change of the spin rate of (10115) 1992 SK has increased the total number of asteroids with YORP detection to ten. In all ten cases, the dω∕dt value is positive, so the rotation of these asteroids is accelerated. It is unlikely to be just a statistical fluke, but it is probably a real feature that needs to be explained.

The problem of searching for optical counterparts of gravitational wave LIGO/Virgo events is discussing. Multi-messenger astronomy boosts the use a huge amount of astronomical data obtained by virtually all observatories around the world. We are discussing different tactics used for observations, problem of search for transients in the extremely large localization error-box of LIGO/Virgo events, and lessons obtained during second observational run of LIGO/Virgo in 2017. In particular we present our experience and results of follow up observations of LIGO/Virgo optical counterpart candidates by Space Research Institute (IKI) Gamma-Ray Bursts Follow up Network (IKI-GRB-FuN).

In the review it is come up with information on the possibilities of breeding programs and the creation of seed orhards of Scots pine (Pinus sylvestris L) as one of the key species of forests in Eurasia, which has significant economic value. Somatic embryogenesis is a promising biotechnological method that allows mass propagation of valuable individuals obtained, including during the implementation of breeding programs. Using the example of various species of the Pinus genus, the main stages of somatic embryogenesis are described. The influence of the conditions and period of cultivation on the effectiveness of somatic embryogenesis and the subsequent conversion of somatic embryos into the plants are considered. Particular attention is paid to the growth and physiology of clones in the field.

At present, chlorophyll meters are widely used for a quick and nondestructive estimate of chlorophyll (Chl) contents in plant leaves. Chl meters allow to estimate the Chl content in relative units - the Chl index (CI). However, using such meters, one can face a problem of converting CI into absolute values of the pigment content and comparing data acquired with different devices and for different plant species. Many Chl meters (SPAD-502, CL-01, CCM-200) demonstrated a high degree of correlation between the CI and the absolute pigment content. A number of formulas have been deduced for different plant species to convert the CI into the absolute value of the photosynthetic pigment content. However, such data have not been yet acquired for the atLEAF+ Chl meter. The purpose of the present study was to assess the applicability of the atLEAF+ Chl meter for estimating the Chl content. A significant species-specific exponential relationships between the atLEAF value (corresponding to CI) and extractable Chl a, Chl b, Chl (a+b) for Calamus dioicus and Cleistanthus sp. were shown. The correlations between the atLEAF values and the content of Chl a, Chl b, and Chl (a+b) per unit of leaf area was stronger than that per unit of dry leaf mass. The atLEAF value- Chl b correlation was weaker than that of atLEAF value-Chl a and atLEAF value-Chl (a+b) correlations. The influence of light conditions (Chl a/b ratio) on the atLEAF value has been also shown. The obtained results indicated that the atLEAF+ Chl meter is a cheap and convenient tool for a quick nondestructive estimate of the Chl content, if properly calibrated, and can be used for this purpose along with other Chl meters.

We proposed the concept of creating automotive computer systems based on the virtualization of transportation processes management. It was proven that the implementation of basic principles and rules of the virtual management of the enterprises of a transportation services market makes it posssible to improve efficiency of operation of transportation and road enterprises of Ukraine. A new approach is proposed to the creation of a unified informational space of the market of transportation services based on using cloud computing. A special feature of such a synergistic approach to the informational development of the market of transportation services is zero capital investment on their implementation and introduction to the transportation and traffic organizations. We investigated interactive monitoring of the chosen route. An artificial neural network for estimating a route is designed. A transportation information matrix is proposed to use a source of information about state of the routes of respective transfer, both of cargo and passengers, in contrast to conventional transportation processes.

In the present paper, the results of the research of biometric and functional parameters of photosynthetic apparatus of Bistorta vivipara from West Spitsbergen are presented and discussed. A high intraspecific variability of biometric parameters (linear dimensions and biomass) was found. The differences found in biomass suggest that biological productivity is associated with the functional activity of the plant individuals. A direct dependence of the biomass on the photosynthetic pigment content per unit dry mass of leaf has been revealed. A high variability of non-photochemical fluorescence quenching (NPQ), basic fluorescence yield (F 0 ), maximal fluorescence yield (F M ) and variable fluorescence yield (F V ) have been shown contrastingly to relatively constant values of the maximum photochemical quantum yield of PS II (F V /F M ) and the coefficient of photochemical fluorescence quenching (qP). Close-to-theoretical-maximum F V /F M values indicated the absence of stress conditions and the presence of regulation systems in chloroplastic photosynthetic apparatus (PA) level functioning during varying microclimate parameters of the daily climate. The relatively constant qP indicated the same photosynthetic activity of the B. vivipara leaves, unaffected by the varying weather conditions. The NPQ data suggest that the non-photochemical quenching acts as a protective mechanism, sustaining the PA in an optimally active state and reducing probability of negative changes to PSII. The revealed high PA adaptability at the level of the plant structure and light-dependent reactions of photosynthesis makes it possible for B. vivipara to develop at a high functional level at various values of environmental factors, which provides for the successful growth of the species in the high Arctic region. The high PA flexibility suggests that B. vivipara is capable of active adaptation in the context of the forecast climate change.

В докладе представлены результаты наблюдений комет с телескопом любительского класса (20-см рефлектор системы Ньютона), оснащенного ПЗС-камерой SBIG ST-8300 с фотометрическими фильтрами. Показано, что с этим инструментом можно успешно решать ряд мониторинговых задач. Обсуждаются точность фотометрии, пределы измерения диаметров кометных ком с малыми апертурами и выявление кометной активности. Сделан вывод о пригодности небольших телескопов для фотометрических исследований. We presents results of comet observations with the amateur-class telescope (20-cm Newton reflector), equipped with the SBIG ST-8300 CCD and photometric filters. It is shown that using this instrument a number of observational tasks can be successfully solved. The accuracy of photometry, as well as subtasks, are discussed. Based on the results of the work carried out, a conclusion was made regarding the suitability of small telescopes for the photometric studies.

Effects of abiotic factors on the parameters of the CO2/H2O exchange in Betula pendula Roth, Populus tremula L., Alnus incana (L.) Moench and Pinus sylvestris L. trees in the middle-taiga subzone of southern Karelia was studied. Carbon and water exchange of woody plants were studied using the portable photosynthesis system LI-COR 6400ХТ (LI-COR Inc., USA) and the pressure chamber Plant Moisture Vessel SKPM 1400 (Skye Instruments Ltd., UK). The results of provided leaf photosynthesis, respiration and stomatal conductance measurements were used in the process-based Mixfor-SVAT model (Olchev et al., 2017) to derive the possible response of CO2/H2O budgets of Karelian forest ecosystems to future climatic changes. Работа выполнена в рамках государственного задания КарНЦ РАН и при частичной финансовой поддержке РФФИ (грант 17−04−01087-а).