共查询到20条相似文献，搜索用时 15 毫秒
1.
In this paper we investigate the influence of a varying gravitation constant on the orbits of celestial bodies. Regarding the eccentric anomaly as an independent variable, we find the solutions to the perturbed equations of motion. In the first order solutions, we find the secular and periodic variations in semi-major axis. For the other orbital elements only periodic variations exhibit. However in the second order solutions, the longitude of periastron and the mean longitude have secular terms. Applying the calculations to six selected binaries, we give the numerical estimations of the variations of orbits. These results are then carefully compared and discussed. 相似文献
2.
随着对外太空探索脚步的加快，人类开始对与太阳系具有相似结构的恒星行星系统越来越感兴趣，因为它们有可能也拥有智慧生命。简单介绍了目前地外恒星行星系统的探测情况，分析了现在比较常用的几种探测方法的可行性和适用范围，重点讨论了利用视向速度法得到的结果及其意义。近年来，各种探索地外行星的小卫星的升空以及探测技术的进步使得大批高质量数据获得成为可能。可以预见，在未来几年内，地外恒星行星系统的探索将会进入一个蓬勃发展阶段。 相似文献
3.
Alessandra Celletti Cătălin Galeş Giuseppe Pucacco Aaron J. Rosengren 《Celestial Mechanics and Dynamical Astronomy》2017,127(3):259-283
We provide a detailed derivation of the analytical expansion of the lunar and solar disturbing functions. Although there exist several papers on this topic, many derivations contain mistakes in the final expansion or rather (just) in the proof, thereby necessitating a recasting and correction of the original derivation. In this work, we provide a self-consistent and definite form of the lunisolar expansion. We start with Kaula’s expansion of the disturbing function in terms of the equatorial elements of both the perturbed and perturbing bodies. Then we give a detailed proof of Lane’s expansion, in which the elements of the Moon are referred to the ecliptic plane. Using this approach the inclination of the Moon becomes nearly constant, while the argument of perihelion, the longitude of the ascending node, and the mean anomaly vary linearly with time. We make a comparison between the different expansions and we profit from such discussion to point out some mistakes in the existing literature, which might compromise the correctness of the results. As an application, we analyze the long-term motion of the highly elliptical and critically-inclined Molniya orbits subject to quadrupolar gravitational interactions. The analytical expansions presented herein are very powerful with respect to dynamical studies based on Cartesian equations, because they quickly allow for a more holistic and intuitively understandable picture of the dynamics. 相似文献
4.
William H. Jefferys 《Celestial Mechanics and Dynamical Astronomy》1971,3(3):390-394
In some perturbation theories it is possible to avoid expansion of the perturbations in powers of the eccentricity, obtaining results in closed form by using the true or eccentric anomaly instead of the mean anomaly. This paper describes an algorithm (which has been programmed for the 6600 computer using the formula manipulation system TRIGMAN) for automatically performing the integrals which arise in these theories. 相似文献
5.
When Kozai (1962) studied the secular resonance of asteroids, he found the so-called Kozai resonance and expressed the analytical
solution with the use of Weierstrass ℘. Here we discuss the case where the disturber is outside a disturbed body and give
the analytical solution of the eccentricity, the inclination and the argument of pericenter with the use of the Jacobi elliptic
functions, which are more familiar than the Weierstrass ℘. Then we derive the Fourier expansion of the longitude of node and
the mean anomaly. The analytical expressions obtained here can be used for any value of the eccentricity and the inclination.
Finally we applied these analytical expressions to several dynamical systems – Nereid, that is a highly eccentric satellite
of Neptune, and newly discovered retrograde satellites of Uranus.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
In the algebraA of functions periodic in the mean anomaly we relate the problem of integrating over the mean anomaly with that of decomposing an element ofA as the direct sum of two functions, one in the kernel of the Lie derivative in the Keplerian flow and one in the image of this Lie derivative. We propose recursive rules amenable to general purpose symbolic processors for accomplishing such decomposition in a wide subclass ofA. We introduce the dilogarithmic function to express in exact terms quadratures involving the equation of the center. 相似文献
7.
M. A. Vashkov’yak 《Astronomy Letters》2005,31(7):487-493
We consider the case of averaging the perturbing function of the Hill problem over the fastest variable, the mean anomaly of the satellite. In integrable special cases, we found solutions to the evolutionary system of equations in elements. 相似文献
8.
Hiroshi Kinoshita 《Celestial Mechanics and Dynamical Astronomy》1977,15(4):501-505
Fourier expansions of functions of velocity in the two-body problem are obtained in terms of both the true anomaly and the mean anomaly. 相似文献
9.
Convergence of the expansions of the disturbing functions in the planar three-body planetary problem
V. G. Sokolov 《Solar System Research》2007,41(2):162-170
In the framework of the planar three-body planetary problem, conditions are found for the absolute convergence of the expansions of the disturbing functions in powers of the eccentricities, with coefficients represented by trigonometric polynomials with respect to the mean, eccentric, or true anomaly of the inner planet. It is found that using the eccentric or true anomaly as the independent variable instead of the mean anomaly (or time) extends the holomorphy domain of the principal part of the perturbation functions. The expansions of the second parts converge in open bicircles, which admit values of the eccentricity of the inner planet in excess of the Laplace limit. 相似文献
10.
《New Astronomy》2017
Despite the now common position that the Pioneer anomaly is not a real gravitational effect but an effect due to the on-board thermal recoil forces – for curiosity’s sake, we here take the suggestion of Nyambuya (2015) where it has been assumed that the Pioneer anomaly – can, in-principle, be attributed to a gravitational effect due to these spacecrafts accreting some material from a rarefied Interplanetary Medium (IPM) in the domain where the Pioneer anomaly has manifested [20 AU ≲ r ≲ 70 AU]. If this assumption is correct, then, the expected Pioneer acceleration of these spacecrafts maybe much smaller than the Pioneer acceleration to cause as noticeable apsidal precession of the outer Solar planets Uranus, Neptune and Pluto, thus making it difficult to rule-out a gravitational origin of the Pioneer anomaly. 相似文献
11.
We study a mean field model of the solar dynamo, in which the non-linearity is the action of the azimuthal component of the Lorentz force of the dynamo-generated magnetic field on the angular velocity. The underlying zero-order angular velocity is consistent with recent determinations of the solar rotation law, and the form of the alpha effect is chosen so as to give a plausible butterfly diagram. For small Prandtl numbers we find regular, intermittent and apparently chaotic behaviour, depending on the size of the alpha coefficient. For certain parameters, the intermittency displays some of the characteristics believed to be associated with the Maunder minimum. We thus believe that we are capturing some features of the solar dynamo. 相似文献
12.
Conway (Celest. Mech. 39, 199–211, 1986) drew attention to the circumstance that when the Newton–Raphson algorithm is applied
to Kepler's equation for very high eccentricities there are certain apparently capricious and random values of the eccentricity
and mean anomaly for which convergence seems not to be easily reached when the starting guess for the eccentric anomaly is
taken to be equal to the mean anomaly. We examine this chaotic behavior and show that rapid convergence is always reached
if the first guess for the eccentric anomaly is π. We present graphs and an empirical formula for obtaining an even better
first guess. We also examine an unstable situation where iterations oscillate between two in correct results until the instability
results in sudden convergence to the unique correct solution.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
13.
Jaroslav Souček 《Astrophysics and Space Science》1988,141(1):103-131
Using the well-known relation for the mean surface brightness, the author gives the concept of the decision regarding the expansion of the Universe. The most serious obstacle on this way was the low precision of parameter measurements which one could achieve in the past. This paper brings the first step for eventual judgement if the Universe expand or not because the accuracy of measurements has advanced. In this sence, we need some more determinations with present accuracy to give the decisive result because the mean surface brightness must faint by 1.46 mag per square arc sec for red shift of 0.4, and this is sufficient to measure and statistically elaborate it. 相似文献
14.
H. D. Hopkins 《Planetary and Space Science》1972,20(12):2093-2098
The present analysis concerns the longitudinal variation in the development and decay of the equatorial anomaly as observed by the Ariel 3 satellite. Data from about seven hundred equatorial passes of the satellite were used to give a broad longitudinal and local time coverage. 相似文献
15.
Nearly 15 years after the proposal of the superanoxia concept (Isozaki, Y., 1994. Superanoxia across the Permo–Triassic boundary: record in accreted deep-sea pelagic chert in Japan. In: Embry, A.F., Beauchamp, B., Glass, D.J. (Eds.), Pangea: Global Environments and Resources. Memoir, Canadian Society of Petroleum Geologists, 17, pp. 805–812.), it is an appropriate timing to re-evaluate its geological context with the updated dataset. Kakuwa (Kakuwa, Y., 2008. Evaluation of palaeo-oxygenation of the ocean bottom across the Permian–Triassic boundary. Global and Planetary Change 63, 40–56.) lately discussed that the deep-sea anoxia across the Permian–Triassic boundary (P–TB) may have been much shorter than previously proposed, on the basis of ichnofabrics and geochemical data; however, his interpretations of the data do not appear straightforward nor persuading, and thus his claim is likely misled. Here we raise comments to his explanation on the following four issues: 1) invalid application of ichnofabric indices for shallow sea sediments to deep-sea cherts, 2) misinterpretation of Ce anomaly as a redox indicator, 3) improper application of various redox sensitive trace elements, and 4) questionable interpretations of δ34S data of pyrites. 相似文献
16.
17.
Position and velocity perturbations in the orbital frame in terms of classical element perturbations
Stefano Casotto 《Celestial Mechanics and Dynamical Astronomy》1993,55(3):209-221
The transformation of classical orbit element perturbations to perturbations in position and velocity in the radial, transverse and normal directions of the orbital frame is developed. The formulation is given for the case of mean anomaly perturbations as well as for eccentric and true anomaly perturbations. Approximate formulas are also developed for the case of nearly circular orbits and compared with those found in the literature. 相似文献
18.
The scattering in the neighbourhood of the Sun is investigated on photographs taken in Pic-du-Midi Observatory during the partial solar eclipse of february 25th 1971. Briefly mentioned, the diffraction theory is used to determine the image of a crescent with incoherent illumination, and to compare the ‘diffracted’ isophote curves with those drawn from the plates. An accurate photometry of the plates enables us to give charts of the electronic density in a coronal sector, and also to determine some physical quantities, values of which are rather uneasy to get from usual observations, such as the polarisation ratio and the electron density of the first Fexiv excited level. In this last case, an original calculation was used to find the source function. A superimposition of a coronal enhancement in white light with a monochromatic arch, gives coherent results without any major assumptions. These assumptions are explained step by step and some interpretations are compared with those given by other authors. 相似文献
19.
Abstract— Historically, there have been a range of diameter estimates for the large, deeply eroded Vredefort impact structure within the Witwatersrand Basin, South Africa. Here, we estimate the diameter of the transient cavity at the present level of erosion as ～124–140 km, based on the spatial distribution of shock metamorphic features in the floor of the structure and downfaulted Transvaal outliers. Taking erosion into account (<6 km) and scaling to original final rim diameter, an estimate of close to 300 km for the rim diameter is obtained. Independent estimates of the final rim diameter, based on an empirical relation of central uplift diameter to rim diameter, spatial distribution of pseudotachylites, and concentric large scale structural patterns, give a similar estimate of close to 300 km for the original final rim diameter. An impact structure of this size is expected to have had an original multi-ring form. At this size, the Vredefort impact structure encompasses the bulk of the Witwatersrand Basin, which appears to owe its preservation to the Vredefort impact. In addition, the Vredefort impact event may have been the thermal driver for some of the widespread hydrothermal activity in the area, which, in recent interpretations, is believed to be a component in the creation of the world-class gold deposits of the Witwatersrand Basin. 相似文献
20.
An object located approximately atl=8°,b=–4° with a mean radial velocity of –212.3 km s–1 has been observed in the 21 cm neutral hydrogen line. The mean weighted velocity dispersion is 11.2 km s–1 and the total mass is estimated to be 190R
2 (kpc) solar masses. We discuss possible interpretations of the origin and nature of this object. The most likely interpretation is that we observe an expanding object which has been ejected from the galactic nucleus. 相似文献