scholarly journals ORBITAL EFFECTS OF A TIME-DEPENDENT PIONEER-LIKE ANOMALOUS ACCELERATION

2012 ◽  
Vol 27 (12) ◽  
pp. 1250071 ◽  
Author(s):  
L. IORIO
Keyword(s):  
Major Axis ◽  
Time Dependent ◽  
Semi Major Axis ◽  
Orbital Parameters ◽  
Estimated Parameters ◽  
Secular Variations ◽  
Dependent Component ◽  
Orbital Revolution ◽  
Anomalous Acceleration ◽  
The Impact

We work out the impact that the recently determined time-dependent component of the Pioneer Anomaly (PA), if interpreted as an additional exotic acceleration of gravitational origin with respect to the well-known PA-like constant one, may have on the orbital motions of some planets of the solar system. By assuming that it points towards the Sun, it turns out that both the semi-major axis a and the eccentricity e of the orbit of a test particle would experience secular variations. For Saturn and Uranus, for which modern data records cover at least one full orbital revolution, such predicted anomalies are up to 2–3 orders of magnitude larger than the present-day accuracies in empirical determinations of their orbital parameters from the usual orbit determination procedures in which the PA was not modeled. Given the predicted huge sizes of such hypothetical signatures, it is unlikely that their absence from the presently available processed data can be attributable to an "absorption" for them in the estimated parameters caused by the fact that they were not explicitly modeled. The magnitude of a constant PA-type acceleration at 9.5 au cannot be larger than 9×10-15 m s-2 according to the latest observational results for the perihelion precession of Saturn.

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 Influence of non-gravitational effects on the Centaur upper stage of the Surveyor 2 spacecraft

2021 ◽  
Vol 2103 (1) ◽  
pp. 012029
Author(s):  
A A Martyusheva ◽  
A V Devyatkin
Keyword(s):  
Solar Radiation Pressure ◽  
Close Approach ◽  
Major Axis ◽  
Semi Major Axis ◽  
Maximum Displacement ◽  
Gravitational Effects ◽  
Yarkovsky Effect ◽  
Upper Stage ◽  
The Impact ◽  
Heliocentric Orbit

Abstract A small near-Earth asteroid, discovered by the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) on September 17, 2020, turned out to be a part of the Centaur upper stage of the Surveyor 2 spacecraft launched by NASA on September 20, 1966 and subsequently crashed. This object had moved in a heliocentric orbit until it was under the influence of Earth’s gravitational field. As a result, a close approach to the Earth took place at a distance of about 50000 km on December 1, 2020. Despite the fact that the Centaur escaped back into a new orbit around the Sun in March 2021, it is of special interest for research, in particular, to consider the impact of non-gravitational effects on its orbital characteristics. Thus, it was calculated that the maximum displacement of the object trajectory due to the influence of solar radiation pressure over 15 years (the next close approach will take place in 2036) can be about 10.3-13.5 km, depending on the albedo. Estimations of the Yarkovsky effect showed that the magnitude of the expected change in the semi-major axis of Centaur’s orbit is from -8.1 • 10−13 to 1.6 10−13, depending on the angle of its rotation.

scholarly journals Ring dynamics around an oblate body with an inclined satellite: the case of Haumea

2020 ◽  
Vol 643 ◽  
pp. A67
Author(s):  
Francesco Marzari
Keyword(s):  
Equatorial Plane ◽  
Protective Factor ◽  
Central Body ◽  
Orbital Plane ◽  
Major Axis ◽  
The Body ◽  
Triaxial Ellipsoid ◽  
Semi Major Axis ◽  
Short Timescale ◽  
The Impact

Context. The recent discovery of rings and massive satellites around minor bodies and dwarf planets suggests that they may often coexist, as for example around Haumea. Aims. A ring perturbed by an oblate central body and by an inclined satellite may disperse on a short timescale. The conditions under which a ring may survive are explored both analytically and numerically. Methods. The trajectories of ring particles are integrated under the influence of the gravitational field of a triaxial ellipsoid and (a) massive satellite(s), including the effects of collisions. Results. A ring initially formed in the equatorial plane of the central body will be disrupted if the satellite has an inclination in the Kozai–Lidov regime (39.2° < i < 144.8). For lower inclinations, the ring may relax to the satellite orbital plane thanks to an intense collisional damping. On the other hand, a significant J2 term easily suppresses the perturbations of an inclined satellite within a critical semi-major axis, even in the case of Kozai–Lidov cycles. However, if the ring is initially inclined with respect to the equatorial plane, the same J2 perturbations are not a protective factor but instead disrupt the ring on a short timescale. The ring found around Haumea is stable despite the rise in the impact velocities that is due to the asymmetric shape of the body and the presence of a 3:1 resonance with the rotation of the central body. Conclusions. A ring close to an oblate central body should be searched for in the proximity of the equatorial plane, where the J2 perturbations protect it against the perturbations of an external inclined satellites. In an inclined configuration, the J2 term is itself disruptive.

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 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⊙).

scholarly journals The Impact of Transiting Planet Science on the Next Generation of Direct-Imaging Planet Searches

2008 ◽  
Vol 4 (S253) ◽  
pp. 556-559
Author(s):  
Joseph C. Carson
Keyword(s):  
A Priori ◽  
Major Axis ◽  
Next Generation ◽  
A Priori Information ◽  
Direct Imaging ◽  
Semi Major Axis ◽  
Absorption Bands ◽  
Imaging Results ◽  
Priori Information ◽  
The Impact

AbstractWithin the next five years, a number of direct-imaging planet search instruments, like the VLT SPHERE instrument, will be coming online. To successfully carry out their programs, these instruments will rely heavily on a-priori information on planet composition, atmosphere, and evolution. Transiting planet surveys, while covering a different semi-major axis regime, have the potential to provide critical foundations for these next-generation surveys. For example, improved information on planetary evolutionary tracks may significantly impact the insights that can be drawn from direct-imaging statistical data. Other high-impact results from transiting planet science include information on mass-to-radius relationships as well as atmospheric absorption bands. The marriage of transiting planet and direct-imaging results may eventually give us the first complete picture of planet migration, multiplicity, and general evolution.

scholarly journals Impact of the Atmospheric Drag on Starlette, Stella, Ajisai, and Lares Orbits

2015 ◽  
Vol 50 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Sośnica Krzysztof
Keyword(s):  
Major Axis ◽  
Radial Component ◽  
Satellite Orbits ◽  
Atmospheric Drag ◽  
Semi Major Axis ◽  
Station Coordinates ◽  
Earth Rotation Parameters ◽  
Out Of Plane ◽  
Along Track ◽  
The Impact

Abstract The high-quality satellite orbits of geodetic satellites, which are determined using Satellite Laser Ranging (SLR) observations, play a crucial role in providing, e.g., low-degree coefficients of the Earth's gravity field including geocenter coordinates, Earth rotation parameters, as well as the SLR station coordinates. The appropriate modeling of non-gravitational forces is essential for the orbit determination of artificial Earth satellites. The atmospheric drag is a dominating perturbing force for satellites at low altitudes up to about 700-1000 km. This article addresses the impact of the atmospheric drag on mean semi-major axes and orbital eccentricities of geodetic spherical satellites: Starlette, Stella, AJISAI, and LARES. Atmospheric drag causes the semi-major axis decays amounting to about ▲a = -1.2, -.12, -.14, and -.30 m/year for LARES, AJISAI, Starlette, and Stella, respectively. The density of the upper atmosphere strongly depends on the solar and geomagnetic activity. The atmospheric drag affects the along-track orbit component to the largest extent, and the out-of-plane to a small extent, whereas the radial component is almost unaffected by the atmospheric drag.

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