Взаимооействие Излучения Рентгеновскооо Истооника с АтмосФерой Нормальной Звезды в Тесных Двойных Системах

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The high-dispersion continuous ultraviolet solar spectrum and the Balmer-jump

Among the intensities, determined at about 200 wavelengths between 3000 and 4100 Å in the spectrum of the centre of the sun's disk (Houtgast, 1965), the 32 highest ones (windows) were plotted and compared with absolute intensities given by other authors.The intensities in between the Fraunhofer lines from 3600 to 4000 Å, as determined here for the first time with high dispersion, reveal a detailed picture of several absorption features, one of which can be attributed to a Balmer jump of 0.03, a value in accordance with that found for stars and in agreement with the strengths of the high Balmer lines.The much higher value of the Balmer jump for the sun, as quoted in literature, in reality refers to the total intensity jump between 4000 and 3600 Å, which is mainly due to the crowding of Fraunhofer lines.     

Метагалактические протоны сверхвысоких энергий

, . 2.7°- . . . E3×10¹⁹ (1.6) .     

Effects of metal abundances on the evolutionary period changes of classical Cepheids

Some peculiarities in the behaviour of a model self-gravitating system described by hydrodynamical equations and isothermal equation of state connected with the presence of thermodynamical fluctuations in real systems were investigated in numerical experiment. The values of density and velocity , , respectively, were computed by numerical code perturbed on each time-step and in each computational cell by random values , for modeling such fluctuations. Perturbed values _i = _i + _i ,v _i = _i + v _i were used to initiate the next step of computations. This procedure is equivalent to an introduction into original hydrodynamical equations of Langevin sources which are random functions. It is shown that these small fluctuations (= v =0,² =v ² = 10^–8) grow many times in marginally-stable state.     

Spectrophotometry of the corona and a quiescent prominence based on observations of the total solar eclipse of 7 March, 1970 in Mexico

Slit spectrograms of a quiescent prominence and the inner corona (h2.5 arc min) in the range 3400–7000 Å (dispersion 6–10 Å/mm) were obtained. From an analysis of the Stark effect on the Balmer lines (up to number 36) the electron density in the prominence n _e = (7 ± 3) × 10¹⁰ cm^–3 was deduced. The kinetic temperature T _k and the non-thermal velocities _t, found from a simultaneous consideration of the Balmer and metal lines, are T _k 10 000 K and v _t6 km/s. Also the emission measure of the prominence along the line-of-sight was found: ME = 10³¹ cm^–5.In the coronal spectrum 24 coronal lines were found. Thirteen of these lines were identified and measured photometrically to get their absolute intensities, profiles and halfwidths. For nine lines the intensities as a function of the height were studied and on this basis the coronal lines were divided into a few groups. The line-of-sight and non-thermal velocities are _r 10 km/s and _t 25 km/s. The coronal lines originate in at least three types of regions with different temperatures. The emission measure as a function of the ionization temperature was determined. The abundances of four elements of the iron group (V, Cr, Mn, Co) were estimated. The abundances of the other elements of the same group (A, Ca, Fe, Ni), found from EUV-data, are in a good agreement with our observations. The degree of inhomogeneity in the corona was estimated: .     

Rapid simultaneous observations of Feii and Balmer emission lines of X Oph

Sudden brightening of FeII and Balmer (H and H) lines of X Oph was observed on 28–29 May, 1986. Equivalent width of FeII and H lines increased by a factor of two and that for H line by a factor of four, during the brigtening phase of the star. This brightening phenomena has been explained in the framework of Coronal Radiative Instability.     

On the third integral of the galaxy

It is shown here that the third integral of the galaxy, whenever its constant is conserved, defines the same surface as the Hamiltonian, and thus does not constitute anynew integral, but a function of the already known integral of energy. In particular, the third integral and the Hamiltonian are found to possess collinear gradients, in accordance with Poincaré's theorem concerning the characteristic exponents in systems with multiple integrals.     

The continuous spectra of supernovae in the period immediately after eruption

We consider the problem of the influence of electron scattering on the continuous spectrum of an envelope. For the radiation flux out of the envelope we assume an expression (1) obtained by us previously [3]. Computations using formula (1) are carried out for two models of the envelope: gray andpurely hydrogen. As a result we find the values of the following quantities, which characterize the continuous spectrum: the color indices U-B, B-V, V-R, and V-I; the Balmer jump D, and the bolometric correction BC. The values of these quantities are given in tables as functions of the surface temperature To of the envelope and the parameter /, where is the coefficient of electron scattering and is the mean absorption coefficient. We draw conclusions on the role of electron scattering for each model of the envelope.Translated fromAstrofizika, Vol. 37, No. 3, 1994.     

Effect of perturbations on the stability of triangular points. In the restricted problem of three bodies with variable mass

The effect of small perturbations and in the coriolis and the centrifugal forces respectively on the stability of the triangular points in the restricted problem of three bodies with variable mass has been studied. It is found that the range of stability of triangular points increases or decreases depending upon whether the perturbation point (, ) lies in one or the other of the two parts in which the (, ) plane is divided by the line J₈–J₉=0 where J₈ and J₉ depend upon , the constant due to the variation in mass governed by Jeans' law.     

Scanner observations of the Be starsν Gem,κ Ori,β Mon andω CMa

The photoelectric spectrophotometric scans of the Be stars Gem, Ori, Mon and CMa have been analyzed to find out few stellar parameters. The absolute energy distributions of these stars in the wavelength range 350–750 nm have been given. Their effective temperatures and gravities have been estimated from comparisons with non-LTE model atmospheres. The stars Gem and Mon have been found to have Balmer discontinuities in emission. The excess emission in the region 620–750 nm has been observed for Mon and CMa. The evolutionary aspects of these stars are discussed and their masses have been estimated.     

Magnetic fields and flares in the region CMP 20 September 1963

The position of bright knots of 30 flares at their very beginning relative to the high-resolution isogauss maps of the longitudinal component (H ) and maps of the transverse component (H ) of magnetic field are considered for seven days during the passage of the active and large spot group in Sept. 1963 (see Table I and maps on Figures 1–8).The flare bright knots occur simultaneously in regions of opposite magnetic polarity, and the majority of these knots are adjacent to neutral line H = 0, although not coinciding precisely with this line (Figure 9). Lenticular form of flare knots and the motions of bright material of flares is restrained by transversal field H . Also flares are closely associated (83%) with so-called bifurcated regions, where specific crossing of transverse components takes place (Figures 4–5). There is well-expressed (80%) coincidence of flare knots with the strongest (positive or negative) electric currents as determined from the relation j = c/4 rot H. The relation of results obtained to some existing theories of flares is briefly discussed.U.S. Nat. Acad. of Science - U.S.S.R. Acad. Nauk. Exchange Scientist Program; now at CSIRO Division of Physics, Australia.     

Some fundamental elements of universe mechanics

An essential part in the mechanics under study is taking into consideration the effect of motions of the Universe objects upon that of an individual one surrounded by them including those infinitely far from it. Only macro-objects of the Universe are meant here.

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Zusammenfassung Ein wesentlicher Bestandteil der Mechanik unter unserer Betrachtung ist die Berechnung des Einflusses auf die Bewegung eines individuellen Objektes von Bewegungen der Universum Objekte die es umringen einschließlich jene Objekte, die unendlich entfernt sind. Nur Makroobjekte des Weltalles sind in der Absicht dabei.

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Космическое черенковское излучение

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Динамические равновесные плазменные конфигуации и физика магнитосферы

, 1-, 2- 3- . , .     

Alfvén waves in stellar winds

A mathematical model for undamped, toroidal, small-amplitude Alfvén waves in a spherically-symmetric or equatorial stellar wind is developed in this paper. The equations are reduced to a very simple form by using real Fourier amplitudes and the ratio of the inward and outward propagating wave amplitudes, which is interpreted as a measure of the relative influence of wave reflection in the flow, on the solution at a given point. Asymptotic solutions at large distances are found to depend only on one parameter, = / _P - the ratio of wave frequency and critical (or cutoff) frequency which is a flow characteristic; a = 1 divides solutions into two qualitatively different groups. When 1 the asymptotic (r-) ratio of the inward and outward propagating wave amplitudes does not depend on wave frequency and is equal to unity, while the phase shift between them changes; in this case the wave pattern is a standing wave. If > 1 the converse occurs with the ratio of the amplitudes decreasing rapidly as the frequency increases, and the phase shift equals to -1/2, corresponding to a propagating wave pattern. The result is also expressed in terms of velocity and magnetic field perturbations.Existence of a finite incoming wave amplitude solution at the Alfvén critical point indicates that this point is stable with respect to the perturbations which originate at the critical point and spend an infinite time in its vicinity.Special attention is paid to the applicability of the WKB approximation. It is argued that it can be used only in finite intervals which do not contain the Alfvén critical point, with inward propagating waves taken into account through the boundary conditions. It is shown that despite the presence of reflection, the outward propagating wave amplitude can be described reasonably well by the WKB formula, perhaps with different constants in different regions. In this context = 1 divides solutions which cannot be approximated by the WKB estimate at all at large distances (the first group), from those which can with any given accuracy.As an illustration of the analytical behaviour some numerical results are shown using a cool wind model. These are likely to express qualitatively the features of the Alfvén waves in any stellar wind, since the only assumptions about the flow used in the analytical study of the wave equations were that: the flow has small velocity at the base of the corona; it then passes through the critical point, and reaches its finite non-zero limit at infinity.     

The eclipses of starspots

Formulae are set out from which the light loss may be derived in a close binary system in which a component affected by a starspot, of the type considered previously (Budding, 1977) is also in eclipse, in such a way that the starspot itself is undergoing eclipse. In this way the hitherto postponed problem of thecombination of eclipse and maculation effects — which are sometimes believed to be present, e.g., in RS CVn-stars — is treated, and shown to be reducible to expressions involving algebraic or elliptic integrals.A more practical approach using a small-spot approximation is given, and demonstrated on an example. Such an approach should be easy to manage by computer, and is expected to find a ready application in the analysis of active cool, close binaries.     

Околозвездньiе облака поданньiм ультрафиолетовьiх спектров свезл

, ii (2000–3000 Å) i . , i . i (. 2). i i i i + ( 7–10). ii (. 13). ii i i (, 2400 Å) (. 14 15). i i i , iu , i (. 1). i i ii i i . .     

A prominence model based on spectral observations

Intensities and profiles of the H, H, H, K, and D₃ lines are measured in a solar prominence. From the profiles of these lines we estimate T = 6400 K and _t = 5.7 km s^–1. We construct a simple isothermal model which explains the H intensity and profile for an assumed total particle density n _T = 3 × 10¹¹ cm^–3, and a filling factor, = 1/6.From this model we find that the source function in the H line is nearly constant through the prominence. We estimate from the model that the radiative energy loss at the center of the prominence is of the order of 10⁷ erg s^–1 g^–1.     

Cherenkov emissions of Langmuir plasmons and light neutrinosby the flux of neutrinos

We consider the system of neutrino-antineutrino – plasma taking into account theirweak Fermi interaction, when the density of neutrinos andthe plasma particles are rather high and their collective interactionplays a vital role. New fluid instabilities driven by strong neutrino flux in aplasma are observed. It is shown that a bunch of neutrinos, drifting witha constant velocity across a homogeneous plasma, can also induce emission oflower energy neutrinos due to scattering, i.e. the decay of a heavy neutrino_H into a heavy and a light neutrino _L(_HHL) in a plasma. Furthermore we find thatthe neutrino production in stars does not lead in general to energy lossesfrom the neutron stars.     

О лагранжевых и зйлеровых решеиях обощенной задачи трех тел

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This paper is a continuation and a generalization of one published earlier (Duboshin, 1969): it discusses the problem whether there exist the Lagrangian and the Eulerian solutions of the generalized three-body (material points) problem. Every point in this generalized problem acts on another, one with a force (attractive or repulsive) directed along the straight line passing through these points, and in an arbitrary manner depending on time, mutual distance and its derivatives, the first and the second. Here, generally speaking, the third axiom of dynamics (law of action and reaction) is not presupposed as fulfilled, that is, it is supposed that every two material points interact in a different way.This most general assumption being made, we establish the conditions which must dictate the laws of the interactions, so that the three points can always remain at the apexes of the equilateral triangle (Langrangian solution), or remain always on a straight line (Eulerian solution).The author believes that such general treatment of the three-body problem can be useful for theoretical studies in celestial mechanics and also for practical applications in the study of isolated stellar systems.