共查询到20条相似文献，搜索用时 171 毫秒
1.
А. П. Маркеев 《Celestial Mechanics and Dynamical Astronomy》1973,8(2):307-322
. . ,e, , . . e, . , .
Stability of the librational triangular points of the three-dimensional elliptic restricted three-body problem is studied. The problem is solved in the non-linear statement at the small values of eccentricity.For all values ofe, , besides ones which correspond to the resonances of the third and the fourth order the librational points are stable taking into account the terms up to the fourth order in the normal form of the Hamiltonian function of the perturbed motion.At sufficiently smalle and the non-stability in sense of Liapunov has been proved. The approximate equations of the boundary of the stability area in the planee, has been obtained. The cause of the non-stability is an equality of the rotational period of the principal attracting masses in the elliptic orbit and the period of oscillation of indefinitely small mass along the direction perpendicular to the plane of their motion.相似文献
2.
A model of a first generation intermediate star of 5M
, with Z=0 has been considered. The model is at an advanced stage of its evolution and has a double shell burning. It burns helium in the inner shell, and hydrogen, via CNO cycle, in the outer shell.
=(log/log)
T
and
T
=(log/logT)
were computed allowing for the oscillations of the relative mass abundance of the reagents in nuclear reactions. Including
=(log/log)
T
and
=(log/logT)
of mean molecular weight and the effect of the oscillations of abundances due to nuclear reactions, stability was studied. Contrary to the results of the static calculations, we found that instability due to the excitation mechanism provided by the high temperature sensitivity of energy generation rate propagates up to the surface. Thus the model in question was found to be unstable against radial adiabatic pulsations, in its fundamental mode. 相似文献
3.
Paul S. Wesson 《Astrophysics and Space Science》1978,54(2):489-495
An exact solution of Einstein's equation is stated in which the density (), pressure (p), scale factorS and metric coefficients are functions of only one dimensionless self-similar variable,ct/R, wheret is cosmic time andR is a co-moving radial coordinate. The solution represents a cosmology that begins as a static sphere having R
–2 and evolves into an expanding model which is pressure-free and has a hierarchical type of density law ( R
–, approximately, with =a number, 02). It is suggested that this model should supersede the previous models of Wesson and other workers, since it appears to be the simplest cosmology for a hierarchy. 相似文献
4.
We discuss imaging with arrays in the thermal IR. Aspects of the design and performance of the Golden Gopher, an infrared array camera are presented. This instrument operates in a high-background environment, for ground-based astronomical imaging from 5 to 27 m. It is built around a 20×64 element Si:As Impurity Band Conduction (IBC) device manufactured by GenCorp Aerojet Electronic Systems Division, and has a noise-equivalent flux density (NEFD) of 23.5mJy min
-1/2 arcsec-2 at =10m, =1m, on the Mt. Lemmon 1.5m telescope. We present and discuss a sample of the data. In addition we discuss the design and expected performance of the Long Wavelength Spectrometer which is now under construction for the Keck telescope. 相似文献
5.
6.
, . : , . , . . ( ) . . . HZ Her=Her X1, . . , . , ., hv 15–30 . , . Sco X1 . 相似文献
7.
Г. А. Гурзадян 《Astrophysics and Space Science》1979,64(1):3-23
2800 Mgii (. 1). (N
+/N
11000) , , (N
+/N
110). , . —, , . — . : ; 0.002 1 , 0.1 ; () 100 –3; ; ; , 10
; 10–4
1
. 2800 Mgii . 相似文献
8.
V. F. Litvin F. M. Holzmann B. S. Taibin A. V. Smirnov E. T. Grebenkina V. N. Baryshnikov V. V. Orlov J. P. Anosova G. D. Polyakova 《Astrophysics and Space Science》1994,215(2):245-261
The diagramV - log(1 +z
e
) as function of (, ) is considered for the quasars. HereV is the apparent visual magnitude,z
e
is the emission line redshift, and are the equatorial coordinates. Two opposite extreme spots NE and SE are observed on the sky, where the inclination of the straight line fitting the dependenceV - log(1 +z
e
) is maximum and minimum. The coordinates of the centres of these extreme spots are (
NE,
NE) = (282°, +42°) and (
SE,
SE) = (70°, -38°) with errors 5°. A hypothesis of the Superattractor (SA) is proposed to explain such an effect. Two independent tests of this hypothesis are realized. First, the dependence or the frequency a of the absorbers in QSO spectra on (, ) is investigated. A region of the larger a is found. The coordinates of its centre are (, ) = (82°, - 10°) with error 5°. Second, the cases ofz
a
>z
e
are plotted in the Mercatorial projection (, ). The most of the casesz
-z
e
> 0.02 are concentrated within the circle with radiusR = 34° and centre (, ) = (50°, - 15°). The both anomalous regions overlap the Southern extreme spot around SE. The SA direction is (, ) = (67°, -21°) with errors about 12°. The redshift of SA isz
SA = 1.7 ± 0.3 that corresponds to the distancer
SA = (3100 ± 300)h
–1 Mpc for the Hubble constantH
0 = 75h kms–1 Mpc–1. The SA mass isM
SA ~ 1018-1020
M
. The orientation of the normal to the quasiperiodical large-scale sheet structure on the sky occurs near SA. 相似文献
9.
10.
Л. Г. Лукьялов 《Celestial Mechanics and Dynamical Astronomy》1976,13(4):455-464
, . . . .
Some asymptotic solutions in the restricted problem of three bodies by L. G. Lukjanov.
Some particular solutions of the plane restricted problem of three bodies in the form of Liapunov's series are obtained. These solutions asymptotically approach the Lagrange solutions. Convergence is proved.相似文献
11.
Jiehao Huang Qiusheng Gu Hongjun Su Zhaohui Shang 《Astrophysics and Space Science》1996,235(1):109-116
We report on a new ESB source, as defined by Allenet al. (1991), with Wolf-Rayet (WR) bands in its optical spectrum. The WR bump at 4605-4686 is detected. The bump consists of broad HeII 4686, NV4605-4619, NIII4634-41, and possibly, CIII4647-52 emission. The narrow nebular lines are clearly discernable on our spectrum. The number of WR stars derived from the luminosity of HeII4686 is about 8100. The oxygen abundance is about 9.06×10–4, greater than the solar value. 相似文献
12.
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. 相似文献
13.
Masaya Saitou 《Astrophysics and Space Science》1989,162(1):47-56
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. 相似文献
14.
, (DM) (RM). , DM RM N
e
= n
e
ds. M
e
= n
e
H cos ds ; . Lerche (1970a, b) , DM RM N
e
M
e
. . 相似文献
15.
. - . . , . - . - , , , -. ., , .
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
16.
, () , , ( =2) , . (, , ). ( =0,5) . 相似文献
17.
18.
Corrections are given which transform the Tables of the solar radiation data (Labs and Neckel, 1968) into the International Practical Temperature Scale of 1968. Additionally, for the adjustment of the data of the true continuum and the corresponding line blanketing as well, the veiled line effect mentioned first by Carbon et al. (1968), but studied in more detail by Holweger (1970a), has been considered also.The corresponding corrections of the solar irradiance result in an improved value of the spectrophotometric solar constant: S = 1.947 cal cm-2 min-1 or 0.1358 W cm-2. Two Tables presenting the highest (window-) intensities and the corrected irradiance data have been added. 相似文献
19.
We found that the structure of the Universe can be characterized by a set of actions
s
. This means that some discontinuous phenomena in the Universe can be considered as large-scale quantum effects. The behaviour of matter on a typical scale is determined by the behaviour of matter on other scales through the interactions. 相似文献
20.
В. А. Гаген-Торн 《Astrophysics and Space Science》1980,73(2):279-294
J 287 1972–1976. , . . J ( ), () . (0=80°) . J 287 ¶ . p=42.8%, 0=101°. (50%). 相似文献