共查询到20条相似文献，搜索用时 171 毫秒
1.
. . .
, 相似文献
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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2.
We present a set of maps of the star-forming regions S140, Re 50, and Mon R2 in theJ, H, andK infrared bands (i.e., 1.2, 1.65, and 2.2 m), obtained with a resolution of 7 and 14 arc sec at the infrared 1.5 m TIRGO telescope, with the TIRGO InSb single channel photometer operating in a mapping mode.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain. 相似文献
3.
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English translation will appear in the next issue ofAstrophys. Space Sci.
Receipt delayed by postal strike in Great Britain 相似文献
The structure of rotating magnetic polytropes is considered in Roche approximation. Investigation of the influence of poloidal as well as toroidal magnetic fields on the conditions of the beginning of matter outflow due to rotational instability is carried out. The influence of the turbulent convection and twisting of magnetic force-lines on the time of smoothing of differential rotation is considered. The estimate of the magneto-turbulence energy generated by differential rotation is presented. Both maximum possible energy output and duration of the quasi-statical evolution phase up to the appearance of hydrodynamic instability due to the effects of general relativity are calculated for supermassive magnetic polytropes of index three with uniform or differential rotation. The radius-mass relation is obtained for supermassive differentially-rotating magnetic polytropes referring to the longest part of the quasi-statistical evolution stage; some consequences are pointed out, including the period-luminosity relation.The evolution of the considered models of supermassive rotating magnetic polytropes with different character of rotation and different geometry of a magnetic field is discussed.The results obtained are summarized in the last section.
English translation will appear in the next issue ofAstrophys. Space Sci.
Receipt delayed by postal strike in Great Britain 相似文献
4.
( , 1977; , 1977). , , , . . 相似文献
5.
The statistical study of the individual light curves of magnetic close binary system AM Herculis obtained in 1978–1988 led to the following conclusions: (a) there is a dependence of the amplitude of brightness variations on the luminosity; (b) the shape of the phased light curves is statistically dependent on the luminosity; (c) the photometric period underwent cyclic changes, the phase of minimum is correlated with luminosity. These results confirm the main observational predictions of the swinging dipole model (Astrophys. Space Sci., 1987,131, 557), but the details are to be investigated during the international programme Polar of coordinated observations of AM Her (27 July–8 August, 1989).Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain. 相似文献
6.
uvby
photometry has been done for early-type stars in the surroundings of the shell star Ori. The reddening maps show the presence of irregularly distributed absorbing material.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain. 相似文献
7.
А. М. Крымский Л. С. Марочник П. Д. НаселБский Н. В. Пелихов 《Astrophysics and Space Science》1978,55(2):299-324
=qr, I II (Marochniket al., 1975 a, b), . , II; , . , , ye , . . t
g. 相似文献
8.
Some potentials for a stationary stellar system model with point-axial symmetry and equatorial plane of symmetry that verifies Chandrasekhar's postulates have been obtained.Paper presented at the 12th European Astronomical Meetings of the IAU on European Astronomers Look to the Future, held 8–11 October, 1990, Davos, Switzerland. 相似文献
9.
The detection of high late-time luminosity in the type-II plateau supernova 1988A about 500 days after maximum indicates that some mechanism is still providing large amounts of energy to the supernova at this very late phase.We present a review of the observations of this supernova at different phases, and examine the possible mechanisms that can power the late light curve in the classical type-II plateau scenario.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8, July, 1989, Tenerife, Canary Islands, Spain. 相似文献
10.
P. López de Coca A. Rolland R. Garrido E. Rodriguez 《Astrophysics and Space Science》1990,169(1-2):211-213
Empirical period-luminosity-colour (P-L-C) relations are obtained for the four lowest modes corresponding to radial pulsations. Agreement with predicted values indicates that, in general, both Strömgren photometric calibration and pulsation theory work well for these stars.Paper presented at the 11 th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain. 相似文献
11.
G. Soucail 《Astrophysics and Space Science》1990,171(1-2):283-287
Photon-counting techniques have been applied to a study of the movement of the image of an unresolved star at the 50 cm telescope of the Royal Academy of Sciences, at the Roque de los Muchachos Observatory. The temporal autocorrelation function of such movement has been computed, the results are discussed in terms of atmospheric turbulence and in relation to high-resolution imaging.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain. 相似文献
12.
A possibility of developing the analytical theory of perturbed motion for a balloon-satellite influenced by solar radiation pressure force is analysed here on the basis of the limit case modification of the two fixed centers problem whose force-field is a superposition of the Newtonian central field and a homogeneous one. Such an approach enables us in the intermediate orbit already to take into account the effect of a constant force, all coordinates of a satellite being expressed as functions of some monotonically increasing variable by means of inversion of elliptic quadratures. The relations between canonical constants of the intermediate orbit and a quasikeplerian elements coinciding in the absence of solar radiation pressure with keplerian ones are derived. The numerical results and illustrating the perturbations in the radius-vector of the intermediate orbit of a balloon-satellite of the Echo-I type are given.
-, , , . , , . , . , - - -I.相似文献
13.
O. Engvold V. Hansteen O. Kjeldseth-Moe G. E. Brueckner 《Astrophysics and Space Science》1990,170(1-2):179-183
The ultraviolet spectrum of a large prominence has been observed with the High Resolution Telescope and Spectrograph (HRTS) on SPACELAB 2, 5 August, 1985. The spectrum covers the wavelength range 1335–1670 Å and shows numerous emission lines from gas at chromospheric and transition region temperatures. An Atlas of the prominence spectrum has been made showing absolute calibrated intensities on an accurate wavelength scale. The Atlas includes for comparison the corresponding UV-spectrum from an average quiet solar region.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain. 相似文献
14.
M. L. García-Vargas A. I. Díaz R. J. Terlevich E. Terlevich 《Astrophysics and Space Science》1990,171(1-2):65-69
We present a stellar population synthesis model for the UV spectrum of the peculiar galaxy NGC 1672, computed with the use of theIUE Atlas Library of Stellar Spectra.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain. 相似文献
15.
T. Buchert 《Astrophysics and Space Science》1990,171(1-2):141-145
Three concepts, statistically fair samples, high spatial resolution of pancakes and dynamical thresholding of density are used to define a procedure of extracting the large-scale distribution of luminous matter from pancake-models.Paper presented at the 11 th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain. 相似文献
16.
, , . , . ( , , ), - qqi . - ; , - . , , . 相似文献
17.
. ]Qi . , r=r. . , . H>2G, — , . , . . .
The exact solutions for the equilibrium of rotating gaseous disk with poloidal magnetic field are obtained. The stability of the disk with respect to uniform expansion and contraction is investigated by means of the variational principle. It is shown that if the equilibrium is determined by gravitational and magnetic forces only, the disk is in neutral equilibrium with respect to perturbations of the form r=r. The instability to short-waves perturbations is studied by the quasi-classical method. The analysis shows that if the magnetic field isH>2G, where is the surface density, then these perturbations are stabilized. The configurations of the electrical field induced by the rotation of magnetized disk are found. In conclusion, the questions of the evolution of the disk are discussed in connection with the quasar model when pulsar-like radiation is taken into account.相似文献
18.
Sterling L. Levie Jr. 《Earth, Moon, and Planets》1971,3(3):315-325
A set of twenty-one point masses gravitationally equivalent to the L1 lunar potential model is presented. By construction, the equivalence is valid only in a region of space sampled by Apollo spacecraft. That region is taken to be a finite, torus-shaped shell. When used in place of the L1 model for Apollo 12 lunar orbit determination, the solution set gives spacecraft positions identical to within about 100 m.The solution is developed in two steps: first the L1 potential is examined to determine favorable mass locations, and then the mass values are computed to force an optimum matching of the L1 potential. Therefore the solution set is artificial. It is related to the Moon's actual mass distribution only in its similar gravitational effects in a limited region of space. 相似文献
19.
In our preceding paper {see [L. Sh. Grigorian and S. Gottlöber, Astrofizika (in press)]} we investigated a self-gravitating system consisting of a scalar field and a linear tensor field ik= ki with minimal coupling and with allowance for the action of vacuum polarization effects. In the present paper we investigate the case of a nonlinear tensor field ik. The action S
()
of the field ik is determined by the difference Rik — ik, where Rik is the space-time Ricci tensor and Rik is the analogous quantity constructed using the metric ik=gik+ik induced by ik ( is a free parameter). Here
S
()
coincides with the previously known expression for the action of a linear field ik. Equations of motion are derived for ik in curved space-time. The energy-momentum metric tensor, determining the contribution of ik to the gravitational field equations, is calculated.Translated from Astrofizika, Vol. 39, No. 1, pp. 135–144, January-March, 1996. 相似文献
20.
Radial velocities of OB stars are utilised in order to determine the values of some galactic structure parameters in the solar neighbourhood.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain. 相似文献