Orientation of interstellar and interplanetary grains

The explicit expressions for the orientation distribution function of interstellar and interplanetary dust grains in the anisotropic corpuscular or radiation fluxes, with consideration for the magnetic field influence, are obtained. An orientation is shown to be possible in a medium having an anisotropic temperature, which is usually the case for a non-equilibrium plasma in a magnetic field. It is noted that the small inhomogeneous dust grains should possess a specific rotation of polarization. The orientation of these dust grains is considered. The time required for the orientation is estimated. A possibility of explaining the interstellar polarization and polarization of the cometary radiation is discussed.

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. , . , . . .

     

Радиоизлучение Быстрых космических ионов

, . () . , , , . ( ), , , . . (2.7). ( ₁ k ₁ ,V — , — .) (k ₁) (k) §2 ( (2.14)). , (3.6) (3.4), (3.8) . (3.9)–(3.13) ( (3.9), (3.10) (3.11) , (3.12)–(3.13) ). (3.14), (3.16)–(3.19). - . (3.15). ( (4.14)–(4.15)). (4.23)–(4.25). (4.26)–(4.28). §5. , . ((5.5)–(5.6)). , . (5.10) .     

О колебаниях хвоста магнитосферы в приБлижении квазигидро динамики

-- () ., , , , , . , , . , .     

Метагалактические протоны сверхвысоких энергий

, . 2.7°- . . . E3×10¹⁹ (1.6) .     

Chromospheric variability in late-type dwarfs from high-resolution spectra of Caii H

Precise photometric observations of stars in the double cluster h and Persei reveal a large spread in the colours and magnitudes of the upper Main-Sequence; half of the stars are variables that are Be stars or related stars. The reported age difference between both clusters is found to be spurious. Rotation apparently affects both the intrinsic and the observed colours of the early-type stars in h and Persei. This result questions the validity of photometric calibrations that heavily rely on h and Persei or similar clusters.Paper presented at the 11th European Regional Astronomical Meeting of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

The asymptotic limit of the form-factors α and β product for celestial bodies

The applicability of the properties of central configurations proceeding from the many-body problem to study of gaseous sphere cloud evolution during its gravitational contraction is justified. It is shown that the product runs to a constant value in the asymptotic time limit of simultaneous collision of all the particles of the cloud where is a form-factor of the potential energy and is a form-factor of the moment of inertia.The spherical bodies as well as ellipsoids of rotation and general ellipsoids with a one-dimensional mass distribution (k),k[0, 1] are found to possess the property =const.

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. , - , , ., , - =const., , (k),k[0, 1].

     

Рассеяние света на анизотропных частицах

, — . , , . , , .     

A study of the young open cluster NGC 6611

- . . , . , .     

турбулентноштб в космологии

=qr, I II (Marochniket al., 1975 a, b), . , II; , . , , ye , . . t _g.     

Theory of the Trojan asteroids,IV

In a previous publication (1977) the author has constructed a family () of long-periodic orbits in the Trojan case of the restricted problems of three bodies. Here he constructs the domain of the analytical solution of the problem of the motion, excluding the vicinity of thecritical divisor which vanishes at the exact commensurability of the natural frequencies ₁ and ₂. In terms of thecritical masses m_j(₂), or the associatedcritical energies _j ² (m), is the intersection of the intervals ofshallow resonance, of the form. Inasmuch as the intervals |₂– _j ² |<_j ofdeep resonance aredisjoint, it follows that (1) the disjointed family () embraces the tadpole branch, 0²1, lying in: and (2) despite the clustering of _j ² (m) atj=, the family () includes, for ²=1, an asymptoticseparatrix that terminates the branch in the vicinity of the Lagrangian pointL ₃.In a similar manner, the family () can be extended to the horseshoe branch 1<_{2 2} ² .     

Спэктр тэплового излучения сверхмассивных звезд и рентгеновских источников

- . ( ) . . F(v)v ^– c>0 . , , .

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In the external layers of supermassive stars and thermal sources of X-ray radiation electron scattering contributes more to the opacity than free-free processes. Therefore, the thermal radiation spectrum of supermassive stars must greatly differ from Planckian, The approximate formulae obtained for the radiation spectra are applicable to any objects with a predominant role of electron scattering in the opacity and power dependence of plasma temperature and density on geometrical depth of the layers.In thermal radiation sources with power dependence of plasma temperature on depth of the layer the formation of power radiation spectraF(v)v ^– with >0 with >0 is possible. Such spectra can imitate the presence of non-thermal radiation mechanisms. This effect takes place also in the case of small optical depth on the Thomson scattering. Possibly, this effect is of interest for the theories of X-ray sources and X-ray solar flares.

     

НутационнЫе демпферы спутиков С двойным вращением

(, 1944; , 1962) . , , . , . , .

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Nutational dampers of dual-spin satellites

The paper considers application of the small parameter methods (Artemjev, 1944; Volosov, 1962) in the linear theory of damping the nutating motion of dual-spin satellites. The external moments affecting the satellite are left out of consideration. The influence of the damper on the satellite motion is assumed to be small. As a special case the conditions of stability for the satellite stationary spinning and the optimal parameters ensuring a maximal rate of damping the nutating motion have been obtained.

     

Перенос резонансного излучения И случайные ълуждания Фотонов

. . .

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Transfer of resonance radiation in infinite medium is considered as a process of random walks of photons. Close relation is shown to exist between the problems of transfer of line radiation and the stable distributions of the probability theory. This relation is used as a basis of a new method for the investigation of the asymptotic properties of the radiation field far from the sources.

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Filter observations of prominences in the D3 and Hα lines

D₃ and H pictures of prominences were obtained with a 21-in. Lyot coronograph and a Fabry-Perot etalon used as a narrow band filter. The monochromatic images of quiescent, quasiquiescent and loop-prominences were studied. The comparison of the isophotes of quiescent and quasi-quiescent prominences in D₃ with those in H shows the similarity of the prominence structure at both wavelength, although there is a strong tendency for an increase in the intensity ratio D₃/H in the upper region of prominences. It seems that it is due to lower temperature in the upper regions of prominences. Probably, the relaxation processes establishing ionization equilibrium play some role. Measurements of the knot intensities of the loop-prominence show strong variations of the intensity ratio D₃/H (more than one order of magnitude).     

К теории кривых Блеска сверхновых звезд

, . . . (10R ) ( 10 000R ). NGC 5457, NGC 6946 NGC 5236. , , II I . . . , . . 10⁵⁰÷10⁵² , .     

Non-restricted double-averaged three body problem in Hill's case

A limiting case of the problem of three bodies (m ₀,m ₁,m ₂) is considered. The distance between the bodiesm ₀ andm ₁ is assumed to be much less than that between their barycenter and the bodym ₂ so that one may use Hill's approximation for the potential of interaction between the bodiesm ₁ andm ₂. In the absence of resonant relations the potential, double-averaged by the mean longitudes ofm ₁ andm ₂, describes the secular evolution of the orbits in the first approximation of the perturbation theory.As Harrington has shown, this problem is integrable. In the present paper a qualitative investigation of the evolution of the orbits and comparison with the analogous case in the restricted problem are carried out.The set of initial data is found, for which a collision between the bodiesm ₀ andm ₁ takes place.The region of the parameters of the problem is determined, for which plane retrograde motion is unstable.In a special example the results of approximate analysis are compared with those of numerical integration of the exact equations of the three body problem.

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m ₀,m ₁,m ₂. , m ₀ m ₁. m ₂, m ₁ m ₂ m ₁ m ₂ . , . . , m ₀ m ₁. , . .

     

The mid-infrared structure of the bipolar nebulae AFGL 915, AFGL 618, and AFGL 2688

We have obtained near diffraction-limited images of three bipolar PPN at UKIRT in October, 1993: AFGL 915 (the Red Rectangle), AFGL 618, and AFGL 2688 (the Egg Nebula). Images were taken at unidentified infrared (UIR) emission feature wavelengths and at several continuum wavelengths in the 10 and 20µm atmospheric windows. In all three PPN the emission is dominated by a central point source with fainter emission extending for several arcsec. In AFGL 2688, the mid-IR emission is extended in the same direction as the main optical lobes. In AFGL 915, the UIR feature emission is spatially separated from the central source. The spikes that have been observed at 2µm and give the nebula its rectangular appearance are also visible at 10µm.     

Динамические равновесные плазменные конфигуации и физика магнитосферы

, 1-, 2- 3- . , .     

Eclipse Observations of Compact Sources in the Outer Solar Corona

We report here on high angular resolution observations of solar noise storm sources at a frequency of 75 MHz. The data for the study were obtained at the Gauribidanur Radio Observatory (long.: 77°2612 E, lat.: 13°3612 N) about 100 km north of Bangalore, India, during the solar eclipse of 24 October 1995. Our main conclusion is that there are structures of angular size 2.5 arc min in the outer solar corona.     

εлектроны космических лучей радиогало галактики

,