scholarly journals The dynamical environment of the primary in the triple asteroid (45) Eugenia

2020 ◽  
Vol 29 (1) ◽  
pp. 59-71
Author(s):  
Min Jiang ◽  
Qingtian Ma
Keyword(s):  
Gravitational Potential ◽  
Effective Potential ◽  
Mechanical Energy ◽  
Equilibrium Points ◽  
Dynamical Behavior ◽  
Major Axis ◽  
Semi Major Axis ◽  
Orbital Parameters ◽  
Short Period ◽  
Zero Velocity Curves

AbstractWe investigated the dynamical behavior in the potential of the primary in the triple asteroid (45) Eugenia with the calculation of the full gravitational potential caused by its 3D irregular shape. We presented the whole structure of the gravitational potential and the effective potential of (45) Eugenia in the coordinate planes, and showed the surface height, surface gravitational force accelerations, and the surface effective potential. The surface gravitational environment has been discussed. The zero-velocity curves and the position of external equilibrium points are calculated and showed relative to the 3D shape of the asteroid to help compare the relationship of the characteristic of the gravitational potential and the shape of the asteroid. There are five equilibrium points in the gravitational potential (45) Eugenia. We presented the positions, eigenvalues, topological cases, and stability of these equilibrium points. To analyze the variety of the orbital parameters close to (45) Eugenia, we computed two different orbits and compared the results. The mechanical energy, the semi-major axis, and the eccentricity have two different periods: the long period and the short period. The inclination have three different periods, an intermediate period is occurred. The longitude of the ascending node and the argument of periapsis not only have two periodic terms, but also have a secular term.

scholarly journals Some Special Types of Orbits around Jupiter

Aerospace ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 183
Author(s):  
Yongjie Liu ◽  
Yu Jiang ◽  
Hengnian Li ◽  
Hui Zhang
Keyword(s):  
Gravity Model ◽  
Small Perturbation ◽  
Equilibrium Points ◽  
Major Axis ◽  
Semi Major Axis ◽  
Ground Track ◽  
The Earth ◽  
Degenerate Equilibrium ◽  
The Mean ◽  
Element Theory

This paper intends to show some special types of orbits around Jupiter based on the mean element theory, including stationary orbits, sun-synchronous orbits, orbits at the critical inclination, and repeating ground track orbits. A gravity model concerning only the perturbations of J2 and J4 terms is used here. Compared with special orbits around the Earth, the orbit dynamics differ greatly: (1) There do not exist longitude drifts on stationary orbits due to non-spherical gravity since only J2 and J4 terms are taken into account in the gravity model. All points on stationary orbits are degenerate equilibrium points. Moreover, the satellite will oscillate in the radial and North-South directions after a sufficiently small perturbation of stationary orbits. (2) The inclinations of sun-synchronous orbits are always bigger than 90 degrees, but smaller than those for satellites around the Earth. (3) The critical inclinations are no-longer independent of the semi-major axis and eccentricity of the orbits. The results show that if the eccentricity is small, the critical inclinations will decrease as the altitudes of orbits increase; if the eccentricity is larger, the critical inclinations will increase as the altitudes of orbits increase. (4) The inclinations of repeating ground track orbits are monotonically increasing rapidly with respect to the altitudes of orbits.

scholarly journals On the synergy between Ariel and ground-based high-resolution spectroscopy

2022 ◽  
Author(s):  
Gloria Guilluy ◽  
Alessandro Sozzetti ◽  
Paolo Giacobbe ◽  
Aldo S. Bonomo ◽  
Giuseppina Micela
Keyword(s):  
High Resolution ◽  
Near Infrared ◽  
Major Axis ◽  
High Resolution Spectroscopy ◽  
Correlation Technique ◽  
Temperature Structure ◽  
Low Resolution ◽  
Semi Major Axis ◽  
Species Discovery ◽  
Orbital Parameters

AbstractSince the first discovery of an extra-solar planet around a main-sequence star, in 1995, the number of detected exoplanets has increased enormously. Over the past two decades, observational instruments (both onboard and on ground-based facilities) have revealed an astonishing diversity in planetary physical features (i. e. mass and radius), and orbital parameters (e.g. period, semi-major axis, inclination). Exoplanetary atmospheres provide direct clues to understand the origin of these differences through their observable spectral imprints. In the near future, upcoming ground and space-based telescopes will shift the focus of exoplanetary science from an era of “species discovery” to one of “atmospheric characterization”. In this context, the Atmospheric Remote-sensing Infrared Exoplanet Large (Ariel) survey, will play a key role. As it is designed to observe and characterize a large and diverse sample of exoplanets, Ariel will provide constraints on a wide gamut of atmospheric properties allowing us to extract much more information than has been possible so far (e.g. insights into the planetary formation and evolution processes). The low resolution spectra obtained with Ariel will probe layers different from those observed by ground-based high resolution spectroscopy, therefore the synergy between these two techniques offers a unique opportunity to understanding the physics of planetary atmospheres. In this paper, we set the basis for building up a framework to effectively utilise, at near-infrared wavelengths, high-resolution datasets (analyzed via the cross-correlation technique) with spectral retrieval analyses based on Ariel low-resolution spectroscopy. We show preliminary results, using a benchmark object, namely HD 209458 b, addressing the possibility of providing improved constraints on the temperature structure and molecular/atomic abundances.

scholarly journals 22. The relation between orbits and physical characteristics of meteors

1968 ◽  
Vol 33 ◽  
pp. 217-235 ◽  
Author(s):  
Ľ. Kresák
Keyword(s):  
Major Axis ◽  
Progressive Increase ◽  
Physical Characteristics ◽  
The Other ◽  
Asteroid Belt ◽  
Angle Of Incidence ◽  
Semi Major Axis ◽  
Short Period ◽  
Broad Variety ◽  
Bona Fide

The relation of physical characteristics of meteors to their orbital elements is investigated using Harvard Super-Schmidt data. A set of characteristic indices is defined, allowing for the effects of geocentric velocity, angle of incidence, magnitude and mass, wherever a correction appears appropriate according to the correlations found by Jacchia et al. (1967). The medians for representative meteor samples are plotted in the semi-major axis/eccentricity diagram and the distribution of each parameter is derived. Although the differences are moderate compared to the measuring errors, six regions of different nature can be distinguished.The existence of two families of asteroidal meteors is indicated, one of them brought to crossing with the Earth's orbit by drag effects and the other by collision effects in the main asteroid belt. These meteors are characterized by low and uniform beginning heights, high fragmentation, low ablation, low deceleration, and bright wakes. A direct counterpart to this is represented by meteors moving in short-period orbits of higher eccentricity and shorter perihelion distance, which bear resemblance to the long-period and retrograde cometary meteors. Meteors with perihelion distances of less than 0·15 AU tend to resemble the bona fide asteroidal meteors by a progressive increase of fragmentation and decrease of reduced beginning heights and decelerations as the perihelion approaches the Sun. This is attributed to the selective destruction effects of solar radiation.With the exception of the Draconids, the mean characteristics of meteor showers agree well with those of sporadic meteors moving in similar orbits. It is suggested that the Draconid stream includes a broad variety of meteoric material and that the two peculiar Super-Schmidt meteors on record represent only the less resistive, short-lived component which has already been eliminated from the other showers.

scholarly journals Phase space description of the dynamics due to the coupled effect of the planetary oblateness and the solar radiation pressure perturbations

2019 ◽  
Vol 131 (9) ◽  
Author(s):  
Elisa Maria Alessi ◽  
Camilla Colombo ◽  
Alessandro Rossi
Keyword(s):  
Phase Space ◽  
Solar Radiation ◽  
Radiation Pressure ◽  
Equilibrium Points ◽  
Hamiltonian Formulation ◽  
Solar Radiation Pressure ◽  
Major Axis ◽  
Integral Of Motion ◽  
Semi Major Axis ◽  
Pressure Perturbations

Abstract The aim of this work is to provide an analytical model to characterize the equilibrium points and the phase space associated with the singly averaged dynamics caused by the planetary oblateness coupled with the solar radiation pressure perturbations. A two-dimensional differential system is derived by considering the classical theory, supported by the existence of an integral of motion comprising semi-major axis, eccentricity and inclination. Under the single resonance hypothesis, the analytical expressions for the equilibrium points in the eccentricity-resonant angle space are provided, together with the corresponding linear stability. The Hamiltonian formulation is also given. The model is applied considering, as example, the Earth as major oblate body, and a simple tool to visualize the structure of the phase space is presented. Finally, some considerations on the possible use and development of the proposed model are drawn.

scholarly journals Self-Maintenance Orbits Using The perturbations Due to Air Drag and Due to Earth's Oblateness

2020 ◽  
Vol 24 (1) ◽  
pp. 56-60
Author(s):  
Mohamed R. Amin
Keyword(s):  
Major Axis ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Semi Major Axis ◽  
Third Order ◽  
Air Drag ◽  
Orbital Parameters ◽  
Orbit Satellite ◽  
Low Earth Orbit Satellite ◽  
Earth’S Oblateness

AbstractThe focus of this paper is the design of a self-maintenance orbit using two natural forces against each other. The effect of perturbations due to Earth's oblateness up to the third order on both the semi-major axis and eccentricity for a low Earth orbit satellite together with the perturbation due to air drag on the same orbital parameters were used, in order to create self-maintenance orbits. Numerical results were simulated for a low earth orbit satellite, which substantiates the applicability of the results.

scholarly journals Correspondances Entre Une Theorie Generale Planetaire En Variables Elliptiques Et La Theorie Classique De Le Verrier

1978 ◽  
Vol 41 ◽  
pp. 15-32 ◽  
Author(s):  
L. Duriez
Keyword(s):  
General Theory ◽  
Classical Theory ◽  
Major Axis ◽  
Second Order ◽  
Semi Major Axis ◽  
First Order ◽  
Short Period ◽  
The Masses ◽  
Secular Terms

AbstractIn order to improve the determination of the mixed terms in classical theories, we show how these terms may be derived from a general theory developed with the same variables (of a keplerian nature). We find that the general theory of the first order in the masses already allows us to develop the mixed terms which appear at the second order in the classical theory. We also show that a part of the constant perturbation of the semi-major axis introduced in the classical theory is present in the general theory as very long-period terms; by developing these terms in powers of time, they would be equivalent to the appearance of very small secular terms (in t, t2, …) in the perturbation of the semi-major axes from the second order in the masses. The short period terms of the classical theory are found the same in the general theory, but without the numerical substitution of the values of the variables.

scholarly journals Orbital Parameters of the PSR B1620–26 Triple System

1996 ◽  
Vol 160 ◽  
pp. 525-530 ◽  
Author(s):  
Z. Arzoumanian ◽  
K. Joshi ◽  
F. A. Rasio ◽  
S. E. Thorsett
Keyword(s):  
Proper Motion ◽  
Time Derivative ◽  
Major Axis ◽  
Mass Range ◽  
Pulse Frequency ◽  
Rate Of Change ◽  
Semi Major Axis ◽  
Orbital Parameters ◽  
Error Bar ◽  
Stellar Masses

AbstractPrevious timing data for PSR B1620–26 were consistent with a second companion mass m2anywhere in the range ∼ 10−3– 1M⊙, i.e., from a Jupiter-type planet to a star. We present the latest timing parameters for the system, including a significant change in the projected semi-major axis of the inner binary, a marginal detection of the fourth time derivative of the pulse frequency, and the pulsar proper motion (which is in agreement with published values for the proper motion of M4), and use them to further constrain the mass m2and the orbital parameters. Using the observed value of, we obtain a one-parameter family of solutions, all with m2≲ 10−2M⊙, i.e., excluding stellar masses. Varyingwithin its formal 1σ error bar does not affect the mass range significantly. However, if we varywithin a 4σ error bar, we find that stellar-mass solutions are still possible. We also calculate the predicted rate of change of the projected semi-major axis of the inner binary and show that it agrees with the measured value.

scholarly journals Mass Loss from Contact Binary Systems and their Dynamical Evolution

1980 ◽  
Vol 88 ◽  
pp. 511-515
Author(s):  
Kyoji Nariai
Keyword(s):  
Angular Momentum ◽  
Mass Loss ◽  
Total Mass ◽  
Binary Systems ◽  
Dynamical Evolution ◽  
Major Axis ◽  
Semi Major Axis ◽  
Orbital Parameters ◽  
Contact Binary ◽  
Fractional Mass

When there is mass loss from a binary system, the lost mass carries energy and angular momentum out of the system. Therefore, the remaining system must adjust its orbital parameters to the changing values of the total kinematic energy E and the total angular momentum N as the total mass M decreases. The parameters concerned here are : the fractional mass μ, the semi-major axis a, and the eccentricity e.

scholarly journals Timing of the Binary Pulsar B1259–63

2004 ◽  
Vol 218 ◽  
pp. 429-430
Author(s):  
N. Wang ◽  
S. Johnston ◽  
R. N. Manchester
Keyword(s):  
Major Axis ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Semi Major Axis ◽  
Timing Behavior ◽  
Binary Pulsar ◽  
Orbital Parameters ◽  
Secular Changes ◽  
Period Variations

This paper summarizes the results of 13 years of timing observations of a unique binary pulsar, B1259–63, which has a massive B2e star companion. A small glitch in the pulsar period apparently occurred in 1997 Aug, not long after the 1997 periastron. We found that spin-orbit coupling with secular changes in periastron longitude and projected semi-major axis cannot account for the observed period variations. A model in which step changes in pulsar orbital parameters occur at each periastron accounts best for the observed timing behavior.

scholarly journals Lorentz Scattering of Interplanetary Dust Grains

1985 ◽  
Vol 85 ◽  
pp. 417-420
Author(s):  
P. Barge ◽  
R. Pellat ◽  
J. Millet
Keyword(s):  
Magnetic Field ◽  
Interplanetary Magnetic Field ◽  
Lorentz Force ◽  
Major Axis ◽  
Interplanetary Dust ◽  
The Sun ◽  
Dust Grains ◽  
Semi Major Axis ◽  
Orbital Parameters ◽  
Resonant Character

AbstractThe scattering of dust grains orbits due to recurrent sectors of the interplanetary magnetic field is reinvestigated with a better formalism. Our method reveals the resonant character of the diffusion and is well suited for the problem. The spreads in the orbital parameters are found less important than believed untill now and to vary rapidly with eccentricity and semi-major axis. Only the small dielectric grains with size less than 0.5 μm may be scattered by the Lorentz force fluctuations; the main diffusion occurs in inclination and near the sun (20-60 R⊙).

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