The magnetic field, including hypomagnetic conditions, is a key astrogeophysical factor that requires comprehensive study of its effects on living systems. Planned interplanetary missions will, on the one hand, encounter the absence of Earth’s geomagnetic field and, on the other, face strong inhomogeneity in the spacecraft’s own magnetic field. Of particular interest is how both the amplitude and the spatial characteristics of magnetic-field inhomogeneity affect human cells under laboratory conditions simulating orbital environments. In vitro cell culture under strictly controlled incubator conditions is a common experimental approach in biological research. CO2-incubators provide control over temperature, gas composition, and humidity. Recent studies report that incubators can significantly alter the ambient magnetic field. Here, we show that two types of CO2-incubators substantially modify magnetic-field parameters, and that the nature of these modifications depends on the incubator model. One incubator exhibited pronounced spatial inhomogeneity of the magnetic field, with regions of both low and high field strength. The other incubator, during operation, generated magnetic-field oscillations with period of oscillations about several seconds and peak-to-peak amplitude exceeding the mean value. We found that the magnetic background markedly affects the growth of human embryonic kidney cells. The effect of an ultra-low-frequency (ULF) magnetic field with a period of several seconds was especially pronounced and is relevant to space applications. Nutrient-deficiency-induced stress increased cellular sensitivity to this factor. These results emphasize the importance of weak static and time-varying magnetic fields for cell-growth processes, particularly in combination with other adverse conditions.

Long-term manned space missions require the design and construction of “space greenhouses” to replenish food supplies and regenerate the atmosphere. Increased levels of ionizing radiation outside the Earth’s magnetosphere can significantly affect the efficiency of photosynthesis, the process by which plants use light energy to synthesize organic matter and produce oxygen. Identifying the mechanisms of the effect of ionizing radiation on photosynthesis and determining the optimal parameters for the operation of space greenhouses can help compensate for the impact of space conditions on plant productivity. This paper shows that irradiation of wheat plants (Triticum aestivum L.) at a dose of 100 Gy significantly increases the rate of plant development and disrupts their ability to use light energy in photosynthesis. A range of illumination intensities was found at which the efficiency of light energy use in irradiated plants coincided with this parameter in control plants. The disruption of the connection between photosystem II and the antenna of the light-harvesting complex caused by oxidative stress is assumed to be the mechanism of the identified imbalance in the functioning of the photosynthetic apparatus.

Abstract Using two eruptive filaments as an example, it is shown that smooth axes of filaments can writhe into helical structures during eruption. This is a clear manifestation of kink instability, which, however, is not the trigger of eruption, but its result. The development of instability occurs at a late stage of eruption on a very large scale. This study is a continuation and development of work published earlier in The Astrophysical Journal, which focused only on the initial stage of eruption occurring at a relatively low height. To analyze the phenomena, observation data were used from the AIA (Atmospheric Imaging Assembly) and HMI (Heliospheric and Magnetic Imager) instruments on board SDO (Solar Dynamics Observatory), SECCHI EUVI (Sun Earth Connection Coronal and Heliospheric Investigation, Extreme UltraViolet Imager) on board STEREO (Solar Terrestrial Relations Observatory), LASCO C2 (Large Angle Spectrometric Coronagraph) on board SOHO (Solar and Heliospheric Observatory), as well as observations from ground-based telescopes. Comparison of images of filaments on the disk with calculations of the magnetic field in the corona gives a fairly reliable estimate of their initial height and convincingly indicates the proximity of the filaments to the threshold of eruptive instability, which probably causes eruptions as a result of the development of this instability. These examples contradict the fairly widespread opinion that kink instability usually initiates eruptions of magnetic flux ropes, and eruptive instability ensures their further development.

The results of the analysis of photometric observations of the long-period SU UMa-type dwarf nova MASTER OT J212624.16+253827.2 are presented based on the ZTF, ATLAS, GAIA, and ASAS-SN data obtained in 2018–2023 (HJD 2 456 772–2 460 568) and the Crimean Astrophysical Observatory obtained in 2023–2024 (HJD 2 460 199–2 460 576) at different stages of outburst activity. We found that this observation interval is notable for variations in the supercycle and cycle of the dwarf nova, equal to $${{146}^{d}}{\kern 1pt} - {\kern 1pt} {{184}^{d}}$$ and $${{12}^{d}}{\kern 1pt} - {\kern 1pt} {{37}^{d}}$$ , respectively. For the first time, we determined the orbital period equal to $${{0.0865044(2)}^{d}}$$ , which dominated in the 2018–2023 (HJD 2 458 228–2 458 836) quiescence and the period of negative superhumps $${{0.083}^{d}}{\kern 1pt} - {\kern 1pt} {{0.084}^{d}}$$ , which dominated in 2023–2024 (HJD 2460199–2460576) quiescence. The estimated mass ratio of the system components is 0.21(2).

The parameters of an axisymmetric model for the gravitational potential of the Galaxy have been refined. The basic curve of the Galaxy’s rotation in a distance interval of R ~ 0–190 kpc was constructed using the velocities of masers, classical Cepheids, Red Clump stars, Blue Horizontal Branch stars, halo stars, globular clusters, and dwarf satellite galaxies of the Milky Way. The rotation curve was selected in such a way that there would be no dominant burst of circular velocities in the central ( $$R < 2$$ kpc) region of the Galaxy. As a result, we constructed two two-component models of the galactic potential, which include contributions from the disk and the halo of invisible matter, as well as a three-component model with a small-mass bulge added in advance. These models can be useful in studying the long-term orbital evolution of stars and open and globular star clusters in the central ( $$R < 4$$ kpc) region of the Galaxy. The constructed models were tested for self-consistency by comparing their rotation curves with a set of model curves generated with the Illustris TNG50 software package.

Abstract Numerical simulations of the evolution of the Solar system consisting at the initial stage of five, six, seven, and eight outer planets, as well as a self-gravitating planetesimal disk, were carried out. The dynamical evolution of planetary systems was studied over a time interval of 4 Gyr. In most cases of numerical simulations, either the destruction of planetary systems or the transition of planets to orbits significantly different from modern orbits occurred. However, a number of successful variants, in which the configuration of the orbits of the outer planets after 4 Gyr was close to the present Solar system, were found. The ejection of additional planets can occur at all stages of the evolution of the Solar system. In the variant with eight planets, a case of an additional planet remaining in a distant trans-Neptunian orbit with a perihelion distance of q = 120 AU was found. Despite the great diversity of evolutionary paths of systems with additional planets, distant trans-Neptunian objects were registered in all successful variants. A trend towards an increase in the number of surviving distant trans-Neptunian objects with an increase in the number of additional planets was noted.

Abstract In order to study the Stark broadening of recombination radio lines in Orion A at a wavelength of 13.5 mm, observations of the H93γ, H94γ, H95γ and H65α lines were carried out at the RT22 (FIAN) radio telescope. An excess of the Stark broadening from the theoretical predictions was found for levels with the main quantum number ( n ) in the range of 93–95 with ∆ n = 2, 3. The recombination radio line H82β was also observed together with the H145(12) and H152(14) lines, the latter also showed an excess of the Stark broadening from the theoretical predictions. It is shown that the Stark broadening data of different frequencies can be consistently described in units of velocities by the dependence ~ n 4–4.5 in the range of n values from 70 to 174. For the first time, the density gradient estimates in this HII region were obtained using the Stark broadening. The electron density of the nebula center turned out to be ≈2 times higher than at a distance of 2 $$' $$ –3 $$' $$ from the center.

High star-formation rate and emission from the active galactic nucleus can significantly transform the interstellar medium. In ultra-luminous infrared galaxies, in which the star-formation rate reaches thousands of solar masses per year, the gas and dust are considerably affected by the ionizing radiation, cosmic rays and shock waves, that can be about a factor of 100–1000 larger than typical values in quiet star-forming galaxies. In these conditions, the emissivity of the gas and dust changes: in dense gas, high ionic and molecular transitions become excited, while dust grains are heated to high temperatures. In this paper, we analyze the possibilities for studying the interstellar medium in extreme conditions of ultra-luminous infrared galaxies at redshifts of ~0–3, utilizing the atomic and molecular lines, and dust continuum in far infrared range of 100–500 μm. We discuss the prospect of observations using the instruments of the Millimetron Space Observatory.

The problem of registration of collapsing stars in the Galaxy is considered using two instruments: the optoacoustic gravitational detector OGRAN and the neutrino telescope BUST, located in the underground laboratories of the Baksan Neutrino Obstrvatory of the Institute for Nuclear Research of the Russian Academy of Sciences (BNO INR RAS). An algorithm for joint data processing on the experience of registration of the SN1987A event is presented. The proposed method is illustrated by the current output signals of these instruments.

The results of absorption modeling in the hydrogen Hα 6563 Å and helium 10830 Å lines for hot Jupiter HAT‑P-32b have been presented. The modeling has been performed using a three-dimensional hydrodynamic code together with the Monte Carlo model of Lyα photon transport. A wide range of stellar radiation and atmospheric parameters has been considered. It has been found that the measured spectrally resolved transit absorption in both lines can be well described by model calculations with the stellar radiation in the XUV range limited to 200 erg/cm2/s per 1 AU, the helium content in the planet’s atmosphere is He/H = 2/98, and metallicity is [Fe/H] = –1. It has been shown that absorption in the helium line occurs uniformly in a large volume of the outflowing atmosphere, and in the hydrogen line, it occurs in a layer of 1.5–2.75 planet radii.