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1.
The techniques of Brumberg and Brumberg (1999) based on the use of elliptic anomaly are specified in this paper in two aspects. The iteration technique (Broucke, 1969) to construct short-term semi-analytical theories of motion in rectangular coordinates in lines of Encke and Hill is reelaborated in terms of elliptic anomaly resulting in extending this technique for high-eccentricity orbits. In constructing long-term semi-analytical theories the key point is to integrate trigonometric functions of several angular arguments related to time by different differential expressions. This problem is reduced in the paper to linear algebraic recurrence relations admitting efficient solution by iterations.  相似文献   

2.
RR Lyrae stars,a well-known type of pulsating variable stars,have been known about for more than a century.A large amount of photometric data on RR Lyrae stars has been accumulated by space-and ground-based sky surveys,but the spectral data are relatively poor.Fortunately,the LAMOST sky survey project provides an opportunity to view them from the point of view of spectra.We collect the atmospheric parameters of 1685 RR Lyrae stars provided by the LAMOST catalog,and carry out research by using the reliable T_(eff).We find that there is a clear correlation between their Teff and pulsation periods,which is consistent with the pulsation and evolution theories of RR Lyrae stars.In addition,we focus on those RR Lyrae stars with abnormal temperatures.After analyzing the data from several photometric surveys,we find that some of these temperature anomalies are misclassified variable stars(e.g.,eclipsing binaries,pulsating stars on main sequence),and some are RR Lyrae binary candidates.For the latter,the temperatures of potential companions should be lower and their luminosities should not be neglected(e.g.,red giant stars).We obtain that the ratio of temperature anomaly stars to all the sample stars is 4%,which means that the impact on the further analysis(e.g.,kinematics analysis) is low.We also present the catalogs of spectral anomaly RR Lyrae stars.  相似文献   

3.
In this paper the first variational equations of motion about the triangular points in the elliptic restricted problem are investigated by the perturbation theories of Hori and Deprit, which are based on Lie transforms, and by taking the mean equations used by Grebenikov as our upperturbed Hamiltonian system instead of the first variational equations in the circular restricted problem. We are able to remove the explicit dependence of transformed Hamiltonian on the true anomaly by a canonical transformation. The general solution of the equations of motion which are derived from the transformed Hamiltonian including all the constant terms of any order in eccentricity and up to the periodic terms of second order in eccentricity of the primaries is given.  相似文献   

4.
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   

5.
Abstract— Concentrations of adsorbed water in single mineral grains of Antarctic lunar meteorites were determined with micro infrared (IR) spectroscopy. A relationship was found between the mineral's ability to adsorb water and the extent of Ce anomaly in rare earth element (REE) patterns precisely determined by the isotope dilution method using a thermal ionization mass spectrometer. Asuka (A) 881757, a lunar meteorite from the mare basalt without Ce anomaly, showed no trace of IR absorption due to adsorbed water. On the contrary, Yamato (Y) 791197-109, Y-86032-98, Y-86032-95, Y-791197-115 and Y-82192-55A from the lunar highland exhibiting positive Ce anomaly showed IR absorption due to adsorbed water in some of their minerals. The detected water would be of terrestrial origin, because it was not structurally bound and easy to exchange judging from the spectral band shape. The contrast in concentration of adsorbed water between the lunar highland and the mare basalt is derived from a difference in the density of microfractures in mineral grains. Average concentrations of adsorbed water in the lunar highland meteorites were 3.8 mg/cm3 for pyroxene and olivine, and 1.7 mg/cm3 for plagioclase. This contrast between minerals is noteworthy because it has been known that Ce anomaly of pyroxene and olivine is larger than that of plagioclase both for Antarctic lunar meteorites and some lunar rocks. Furthermore, more adsorbed water was detected for minerals in meteorites that exhibit larger Ce anomaly. The present observations demonstrate that the extent of Ce anomaly correlated with the concentration of adsorbed water, which suggests that active mineral surface resulting in adsorption of water could be a trace of interaction forming Ce anomaly. Terrestrial weathering on Antarctica and REE fractionation on the Moon are discussed for possible origins of the Ce anomaly.  相似文献   

6.
It is the purpose of this paper to study whether the non-ducted propagation in the inner plasmasphere in the presence of the equatorial anomaly might be relevant to daytime whistlers observed on the ground at low latitudes. Realistic models of the equatorial anomaly simulating the satellite observations have been incorporated in the ray tracing computations. It is found that there are two different non-ducted modes able to penetrate through the ionosphere onto the ground; (1) whispering gallery mode around the anomaly field line which is trapped just by the outer boundary of the anomaly, and (2) pro-longitudinal (PL) mode at a latitude around 30° which is supported by the horizontal gradient in the tail of the anomaly. These modes may provide a new interpretation for some whistlers observed on the ground. The properties of these modes are examined in detail and then compared with those of ducted propagation. This study may be useful for distinguishing the propagation mode in future ground-based experiments.  相似文献   

7.
The post-Newtonian gravitoelectric secular rate of the mean anomaly ℳ is worked out for a two-body system in the framework of the General Theory of Relativity. The possibility of using such an effect, which is different from the well known decrease of the orbital period due to gravitational wave emission, as a further post-Keplerian parameter in binary systems including at least one pulsar is examined. The resulting effect is almost three times larger than the periastron advance . E.g., for the recently discovered double pulsar system PSR J0737-3039 A+B it would amount to −47.79 deg yr−1. This implies that it could be extracted from the linear part of a quadratic fit of the orbital phase because the uncertainties both in the linear drift due to the mean motion and in the quadratic shift due to the gravitational wave are smaller. The availability of such additional post-Keplerian parameter would be helpful in further constraining the General Theory of Relativity, especially for such systems in which some of the other post-Keplerian parameters can be measured with limited accuracy. Moreover, also certain pulsar-white dwarf binary systems, characterized by circular orbits like PSR B1855+09 and a limited number of measured post-Keplerian parameters, could be used for constraining competing theories of gravity.  相似文献   

8.
By using a high-precision LaCoste-Romberg gravimeter, continuous and precise measurements were carried out during the March 9, 1997 total solar eclipse in Mohe region in Northeast China. The gravity variations were digitally recorded during the total solar eclipse so as to investigate the possible anomaly of the Sun and the Moon's gravitational fields on the Earth. After the careful processing and analysis of the observed data, no significant anomaly during the very solar eclipse was found. However, there are two ‘gravity anomaly valleys’ with near symmetrical decrease of about 6 ∼ 7 μg at the first contact and the last contact. This is the anomaly phenomenon observed and reported for the first time in the literature. This paper is intended to explain the observed anomaly by conducting the tilt experiment due to the thermal stress and temperature change in the solar eclipse. A new constraint limit on gravitational shielding is thus obtained. Some analysis and discussions are presented although further studies and research are highly needed. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

9.
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   

10.
Photoelectric observations have been carried out during maximum solar activity in order to investigate the variation of the brightness of the lunar surface with the solar cycle and to detect the possiblity of existing colour anomaly. The brightness data, using a wide-passband filter, do not show any evidence of variation with the solar cycle. No colour anomaly is found for the investigated lunar regions, and the doubt that has been felt by some investigators about the nonexistence of certain colour indices' variation with phase is not confirmed.  相似文献   

11.
Time elements are introduced in terms of Keplerian (classical) orbital elements for use with time transformations of the Sundman type. Three different time elements are introduced. One time element is associated with the eccentric anomaly, a second time element is associated with the true anomaly, and a third time element is associated with theintermediate anomaly.Numerical results are presented that show accuracy improvements of from one to two orders of magnitude when time elements are employed along with Sundman time transformations, compared with using time transformations alone.  相似文献   

12.
This paper calls into question the validity of the well-known formulae for the perturbations in the Keplerian elements, over one revolution of an orbit, for the motion of a drag-perturbed artificial satellite. These formulae are derived from Gauss's form of the planetary equations, by averaging over a single revolution of the orbit, and using the eccentric anomaly as the independent variable.It is shown that for light balloon-type satellites in near-circular orbits neither the eccentric anomaly nor the true longitude is a suitable choice of independent variable for the averaging procedure. Under these circumstances, it would seem that simple formulae for the variations in the elements cannot be derived from Gauss's equations.  相似文献   

13.
The Cerro do Jarau structure is possibly the third Brazilian basaltic crater formed in continental flood basalt of the Serra Geral Formation, Paraná Basin, a large igneous province (LIP) in southern Brazil. It is a nearly circular landform with a diameter of approximately 13 km that rises 200 m above the plains of the “pampas” in southern Brazil. In this work, Bouguer anomalies were calculated from gravity accelerations measured on the area of this structure. The residual Bouguer map shows a strong positive anomaly trending NE‐SW, located in the northeastern part of the structure, a feature not commonly associated with impact structures. However, the negative anomaly present in its center and the circular positive anomaly surrounding the central portion are typical of impact structures. The residual Bouguer anomaly varies from ?2 mGal to 8 mGal. The positive circular anomaly is not spatially coincident with the rim of the structure. Based on the interpretation of our gravimetric data, the estimated diameter of the structure is 12 km and the central portion has a diameter of approximately 5 km, both slightly smaller than previously suggested. The Bouguer anomaly map was inverted into a 3D density model using a constrained inversion method with a maximum density contrast of 0.5 g cm?3. This model was interpreted to associate densities with rock types, resulting in a geological model. This geological model is in accordance with the meteorite impact nature of Cerro do Jarau.  相似文献   

14.
Abstract— The 45-km diameter Montagnais impact structure, Nova Scotia, Canada, is characterized by a positive, circular 8 mGal gravity anomaly associated with its central uplift. The negative gravity anomaly, which is expected for a complex crater of this size, is not observed within the structure, and magnetic data lack any well-defined, crater-related signature. The absence of a negative gravity anomaly implies that no low-density zone generally related to fracturing and brecciation exists. Since Montagnais appears well preserved, this zone has not been removed by erosion. Its formation may have been impeded due to the lack of competency in the target rocks. The crater was formed in a shallow marine environment where the lack of strength in the unconsolidated sediments may have prevented the preservation of voids and fractures that cause a negative gravity anomaly as observed over other impact craters. Additionally, the efficient absorption of impact energy by unconsolidated target material may have inhibited fracture/void development. Although the gravity signature of impact craters formed on land is well known, structures occurring in unconsolidated target material, such as continental shelf environments, constitute another signature that should also be recognized.  相似文献   

15.
The resonance terms produced by the effect of direct solar radiation pressure on the motion of a spacecraft in the oblate field of the earth are analyzed. The spacecraft was assumed axially symmetric with a despun antenna and solar panels. A canonical transformation technique is developed, based on the Bohlin technique of expansion in fractional powers, using Lie series and transformation as well as the concept of the Delaunay anomaly. The developed technique, applied to the problem averaged over the mean anomaly, is suitable in the presence of more than one resonant vector.  相似文献   

16.
Abstract— New gravity and magnetic data were obtained along ground profiles across the Roter Kamm impact crater in the southern Namib desert of Namibia. As the traverses of previous studies did not extend sufficiently beyond the crater rim, it had not been possible to adequately determine the regional background values. The gravity results of this study are similar to those obtained by Fudali in 1973, in that a negative, near-symmetrical anomaly was obtained over the crater center. This anomaly conforms to the results expected for a sediment and impact breccia-filled, simple bowl-shaped crater. The magnetic results of this study, however, are different to those previously reported, which is most probably as a result of the longer profiles used in this new study. A slight positive magnetic anomaly was obtained over the crater interior. Short-wavelength, high-amplitude anomalies observed in the vicinity of the crater rim reflect magnetization contrasts that are probably related to brecciation and block rotation. Modelling of the positive magnetic anomaly indicates the possibility of a small magnetic body or lining at the crater floor-breccia interface in the interior of the crater. Also presented is a 10 m contour digital elevation model of the crater and its environs.  相似文献   

17.
Book Review     
The aim of this book is to present techniques for the study of motion of solar system objects in highly eccentric orbits. Instead of using the usual anomalies (mean, true, eccentric), the authors define and use a new kind of anomaly, the elliptic anomaly.In this way, it is possible, in a theory using perturbation series expansions, to make the ratio: (accuracy)/(number of needed terms), higher than in the classical techniques. The book consists of six chapters. The first chapter deals with the elliptic anomaly in the two-body problem and the second chapter presents the general technique to construct first-order perturbation theory in elliptic function expansions. The next three chapters deal with applications of the new technique to artificial satellites and asteroids, in highly eccentric orbits. The last chapter describes the basic algorithms of the theory.The tools developed in the book demand the use of computer algebra, which is implemented by means of Mathematica 3.0.The book is well written and the new technique is clearly presented and related to the existing techniques, making it useful to all those who use analytical or semi-analytical methods for the study of highly eccentric motion. Celestial Mechanics at High Eccentricities, Gordon and Breach Publishers, US$95, GBP 59, EUR 79, ISBN 90-5699-212-0  相似文献   

18.
A comparison is made between the perturbation theories of Hori and Deprit which are based on the use of Poisson brackets. General recurrence formulae are presented for Hori's theory which are analogous to those in Deprit's theory. Explicit relations between the determining functions for the two theories are indicated through the sixth order, these results having been obtained by a novel computer program. A general argument for the equivalence of the theories to all orders is given.  相似文献   

19.
This paper proposes an explanation for the Pioneer anomaly: an unexplained Sunward acceleration of 8.74 ± 1.33 × 10−10 m s−2 seen in the behaviour of the Pioneer probes. Two hypotheses are made. (1) Inertia is a reaction to Unruh radiation and (2) this reaction is weaker for low accelerations because some wavelengths in the Unruh spectrum do not fit within a limiting scale (twice the Hubble distance) and are disallowed: a process similar to the Casimir effect. When these ideas are used to model the Pioneer crafts' trajectories, there is a slight reduction in their inertial mass, causing an anomalous Sunward acceleration of 6.9 ± 3.5 × 10−10 m s−2 which agrees within error bars with the observed Pioneer anomaly beyond 10 au from the Sun. This new scheme is appealingly simple and does not require adjustable parameters. However, it also predicts an anomaly within 10 au of the Sun, which has not been observed. Various observational tests for the idea are proposed.  相似文献   

20.
The Antarctic ice cap is the largest ice sheet of modern times. It is of considerable importance to predict the sea level variability due to the associated changes in ice volume. We present the results of a simple grounded ice sheet model, developed from Oerlemans [Oerlemans, J., 2002. Global dynamics of the Antarctic Ice Sheet, Climate Dynamics 19, 85–93.], in which the net oceanic evaporation influences the ice cap volume in two ways, through changes in: (i) the accumulation rate, and (ii) the mean sea level. The net evaporation changes are driven by the sea surface temperature (SST) anomaly time series of Howard [Howard, W.R., 1997. A warm future in the past, Nature, 388, 418–419.] for the subantarctic Southern Ocean over the period 220 kyr to the present. The effect of the waxing and waning of the northern hemisphere ice sheets is integrated into the model using an independent model, in which ice melting depends on the SST anomaly and ice calving depends on the sea level anomaly. A series of analytical expressions are derived for the related properties of the coupled ocean–ice system applicable over time scales of 100 kyr, which show, in particular, that the Antarctic ice cap volume changes are due mainly to the effects of the northern hemisphere ice sheets on sea level (which influences ice calving), rather than directly to changes in SST, and hence the ice cap volume is greatest during interglacial periods. This conclusion, which is independent of the specification of the ice melting regime for the northern hemisphere ice sheets, strongly suggests that the changes in accumulation flux estimated from the Vostok proxy temperature data and used in other studies of the Antarctic mass balance have been overestimated. A simple expression is also presented for the lag of ice cap volume to SST, and it is found that the predictions for the mean sea level variability are similar to observations for a melting flux of the northern hemisphere ice sheets about twice their accumulation flux due to the net oceanic evaporation, except during major deglaciations when these two fluxes appear to be of similar magnitude.  相似文献   

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