Том 60, № 1 (2016)

The properties of the relative abundances of rapid and slow neutron-capture elements are studied using a catalog containing spectroscopic abundance determinations for 14 elements produced in various nuclear-synthesis processes for 90 open clusters. The catalog also contains the positions, ages, velocities, and elements of the Galactic orbits of the clusters. The relative abundances of both r-elements (Eu) and s-elements (Y, Ba, La, and Ce) in clusters with high, elongated orbits and in field stars of the Galactic thin disk display different dependences on metallicity, age, Galactocentric distance, and the elements of the Galactic orbits, supporting the view that these objects have different natures. In young clusters, not only barium, but also the three other studied s-elements display significantly higher relative abundances than field stars of the same metallicity. The relative abundances of Eu are lower in highmetallicity clusters ([Fe/H] > -0.1) with high, elongated orbits than in field giants, on average, while the [Eu/Fe] ratios in lower-metallicity clusters are the same as those in field stars, on average, although with a large scatter. The metallicity dependence of the [O, Mg/Eu] ratios in clusters with high, elongated orbits and in field stars are substantially different. These and other described properties of the Eu abundances, together with the properties of the abundances of primary a-elements, can be understood in a natural way if clusters with high, elongated orbits with different metallicities formed as a result of interactions of two types of high-velocity clouds with the interstellar medium of the Galactic disk: low-metallicity highvelocity clouds that formed from “primordial” gas, and high-metallicity clouds with intermediate velocities that formed in “Galactic fountains.”

The results of 3D modeling of the formation of the accretion disks of intermediate polars are presented. A model with misaligned rotation axes of accretor and the orbit is onsidered, in which it is assumed that the white dwarf has a dipolar magnetic field with its symmetry axis inclined to the whitedwarf rotation and orbital axes. The computations show that, in the early stages of formation of the disk, the action of magnetic field is able to create the initial (seed) inclination of the disk. This inclination is then supported mainly by the dynamical pressure of the flow from the inner Lagrangian point L₁. As themass of the disk increases, the inclination disappears. Under certain conditions, the disk inclination does not arise in systems with misaligned white-dwarf rotation and orbital axes. The influence of the magnetic field and asynchronous rotation of the accretor may result in the formation of spiral waves in the disk with amplitudes sufficient to be detected observationally.

The current evolutionary stage of the binary systems IC 10 X-1 and NGC 300 X-1, which contain a massive black hole and a Wolf–Rayet star with a strong stellar wind that does not fill its Roche lobe, is considered. The high X-ray luminosity and X-ray properties testify to the presence of accretion disks in these systems. The consistency of the conditions for the existence of such a disk and the possibility of reproducing the observed X-ray luminosity in the framework of the Bondi–Hoyle–Littleton theory for a spherically symmetric stellar wind is analyzed. A brief review of information about the mass-loss rates of Wolf–Rayet stars and the speeds of their stellar winds is given. The evolution of these systems at the current stage is computed. Estimates made using the derived parameters show that it is not possible to achieve consistency, since the conditions for the existence of an accretion disk require that the speed of the Wolf–Rayetwind be appreciably lower than is required to reproduce the observedX-ray luminosity. Several explanations of this situation are possible: (1) the real pattern of the motion of the stellar-wind material in the binary is substantially more complex than is assumed in the Bondi–Hoyle–Littleton theory, changing the conditions for the formation of an accretion disk and influencing the accretion rate onto the black hole; (2) some of the accreting material leaves the accretor due to X-ray heating; (3) the accretion efficiency in these systems is nearly an order of magnitude lower than in the case of accretion through a thin disk onto a non-rotating black hole; (4) the intensity of the Wolf–Rayet wind is one to two orders of magnitude lower than has been suggested by modern studies.

The elemental abundances in the atmosphere of the red dwarf HD 32147, which belongs to the HR 1614 moving groups, are analyzed. The atmospheric parameters determined from spectroscopic data (the condition of equal abundances for neutral and ionized atoms of a given element) differ considerably from those derived from photometry and parallax data. The abundances of several elements are also anomalous, with the anomaly increasing with decreasing ionization potential. It is concluded that this star is a red dwarf displaying solar-like activity; i.e., having dark (cool) spots on its surface, which may sometimes be considerable in size. Modeling synthetic spectra of stars with cool spots on their surfaces, with the spectral lines consisting of two components formed in media with different temperatures, indicate that the spectroscopic atmospheric parameters derived in such cases are incorrect; this can also explain the observed dependence of the elemental abundances on the corresponding ionization potentials. This leads to the conclusion thatHD32147 is indeed a star with solar-like activity. Several other such stars considered as examples display the same anomalies as those of HD 32147. These modeling results are also valid for Ap and Am stars, and are able to explain short-wavelength observations of the Sun and some stars (the FIP effect).

Two new expansions of the force function of two rigid celestial bodies of finite size and arbitrary shape are obtained in Delaunay–Andoyer variables with any degree of accuracy, in the form of a partial sum of an eight dimensional Fourier series. These expansions of the force function contain products of expressions for the momenta and Stokes constants in terms of sines and cosines, whose arguments are linear combinations of the Delaunay and Andoyer angular variables. These representations of the force function are compact and convenient for applications in various problems in celestial mechanics and astrodynamics.

Observations of H₂O maser sources at 1.35 cm associated with extended regions of 4.5-µm emission (indicated as “green” on Spitzer survey maps—so-called Extended Green Objects, EGOs) are reported. EGOs are considered as characteristic signposts of regions of formation of massive stars, which host high-velocity outflows, as well as methanol, water, and hydroxyl masers. The observations were carried out in January–May 2015 on the 22-meter radio telescope of the Pushchino Radio Astronomy Observatory. The sample studied includes 24 EGOs north of declination -29° taken from the Spitzer GLIMPSE survey, together with one of the brightest Class I methanol masers G6.05-1.45 (M8E) and the Class I methanol maser in an IRDC G359.94+0.17. H₂O maser emission was detected toward 11 of the EGOs: G11.94-0.62, G14.33-0.64, G16.59-0.06, G23.01-0.41, G24.943+0.074, G28.83-0.25, G34.3+0.2, G34.403+0.233, G35.20-0.74, G45.47+0.07, and G49.267-0.337. These including the well known H₂O maser in the W44 region, G34.3+0.2. H₂O emission from G28.83-0.25 was detected for the first time, at 77.6 km/s, with a flux density of 19 Jy in January and 16 Jy in February 2015. The source was probably caught at an early stage of the propagation of a shock wave. The Class I methanol masers G359.94+0.17 and G6.05-1.45 (M8E) and 13 of the EGOs were not detected in the H₂O line, with 3s upper limits of ~6-7 Jy. Spectra and maser-emission parameters are given for the detected H₂Omasers, for some of which strong variability of the H₂O maser emission was observed. The detected H₂Omasers, together with the Class I methanol masers and extended 4.5-µm emission, are associated with a very early stage in the development of young stellar objects in the regions of the EGOs. However, this sample of EGOs is not uniform. The presence of 44-GHz Class I methanol masers together with EGOs cannot be considered the only sign of early stages of star formation.