scholarly journals Orbit Determination of 2002 KM6

2019 ◽  
Author(s):  
Catherine Lu ◽  
Hyunjin Lee ◽  
Carter Moyer
Keyword(s):  
Major Axis ◽  
Orbital Elements ◽  
Stable Orbit ◽  
Semi Major Axis ◽  
Integration Program ◽  
Orbital Determination ◽  
The Mean ◽  
Gathering Data

The premise of this research is to determine the orbit of the asteroid 99795 2002 KM6 and predict its trajectory far in the future. Asteroids’ orbits model ellipses and can thus be described by six orbital elements: the semi-major axis, eccentricity, inclination, the longitude of the ascending node, the argument of perihelion, and the mean anomaly. Using Python, our team programmed a series of orbital determination codes, implementing the Method of Gauss to generate the orbital elements with a reasonable level of error. This required gathering data over at least three observations. We then compared these elements to those generated by JPL Horizons to ensure they were reasonable.Our team used the numerical integration program Swift to determine long-term orbital patterns over the next 50 million years. Simulations of 60 different clones of 2002 KM6, randomly sampled from a Gaussian distribution, revealed that the majority of asteroid particles will either get too far or too close to the Sun after 50 million years. A small percentage of them, however, will maintain a stable orbit.

scholarly journals High Order Resonances in the Evolution of the Lunar Orbit

1983 ◽  
Vol 74 ◽  
pp. 3-17
Author(s):  
J. Kovalevsky
Keyword(s):  
Major Axis ◽  
Lunar Theory ◽  
The Moon ◽  
Tidal Effects ◽  
Semi Major Axis ◽  
Natural Satellite ◽  
Variation Of Constants ◽  
The Mean ◽  
Mean Elements

AbstractThis paper deals with the long term evolution of the motion of the Moon or any other natural satellite under the combined influence of gravitational forces (lunar theory) and the tidal effects. We study the equations that are left when all the periodic non-resonant terms are eliminated. They describe the evolution of the-mean elements of the Moon. Only the equations involving the variation of the semi-major axis are considered here. Simplified equations, preserving the Hamiltonian form of the lunar theory are first considered and solved. It is shown that librations exist only for those terms which have a coefficient in the lunar theory larger than a quantity A which is function of the magnitude of the tidal effects. The solution of the general case can be derived from a Hamiltonian solution by a method of variation of constants. The crossing of a libration region causes a retardation in the increase of the semi-major axis. These results are confirmed by numerical integration and orders of magnitude of this retardation are given.

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 Dynamical properties of the Molniya satellite constellation: long-term evolution of the semi-major axis

2021 ◽  
Author(s):  
Jérôme Daquin ◽  
Elisa Maria Alessi ◽  
Joseph O’Leary ◽  
Anne Lemaitre ◽  
Alberto Buzzoni
Keyword(s):  
Major Axis ◽  
Long Term Evolution ◽  
Semi Major Axis ◽  
Satellite Constellation ◽  
Term Evolution ◽  
Dynamical Properties

scholarly journals Creation/destruction of ultra-wide binaries in tidal streams

2020 ◽  
Author(s):  
Jorge Peñarrubia
Keyword(s):  
Globular Clusters ◽  
Galactic Halo ◽  
Local Density ◽  
Formation Rate ◽  
Semimajor Axis ◽  
Major Axis ◽  
Binding Energies ◽  
Semi Major Axis ◽  
The Mean ◽  
Tidal Streams

Abstract This paper uses statistical and N-body methods to explore a new mechanism to form binary stars with extremely large separations (≳ 0.1 pc), whose origin is poorly understood. Here, ultra-wide binaries arise via chance entrapment of unrelated stars in tidal streams of disrupting clusters. It is shown that (i) the formation of ultra-wide binaries is not limited to the lifetime of a cluster, but continues after the progenitor is fully disrupted, (ii) the formation rate is proportional to the local phase-space density of the tidal tails, (iii) the semimajor axis distribution scales as p(a)da ∼ a1/2da at a ≪ D, where D is the mean interstellar distance, and (vi) the eccentricity distribution is close to thermal, p(e)de = 2ede. Owing to their low binding energies, ultra-wide binaries can be disrupted by both the smooth tidal field and passing substructures. The time-scale on which tidal fluctuations dominate over the mean field is inversely proportional to the local density of compact substructures. Monte-Carlo experiments show that binaries subject to tidal evaporation follow p(a)da ∼ a−1da at a ≳ apeak, known as Öpik’s law, with a peak semi-major axis that contracts with time as apeak ∼ t−3/4. In contrast, a smooth Galactic potential introduces a sharp truncation at the tidal radius, p(a) ∼ 0 at a ≳ rt. The scaling relations of young clusters suggest that most ultra-wide binaries arise from the disruption of low-mass systems. Streams of globular clusters may be the birthplace of hundreds of ultra-wide binaries, making them ideal laboratories to probe clumpiness in the Galactic halo.

LRF and TRF test during long-term danazol treatment: increase of the LH and FSH responses but decrease of the prolactin and TSH responses

1983 ◽  
Vol 104 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. Leppäluoto ◽  
L. Rönnberg ◽  
P. Ylöstalo
Keyword(s):  
Clinical Symptoms ◽  
Follicular Phase ◽  
Blood Samples ◽  
Hormone Levels ◽  
Coefficients Of Variation ◽  
The Mean ◽  
Thyroid Hormone Levels ◽  
Low Serum

Abstract. Seven patients suffering from severe endometriosis were treated with danazol 200 mg × 3 daily for 6 months. Clinical symptoms were alleviated and menses disappeared in response to the treatment. After cessation of the treatment the menstrual bleedings returned in 1–3 months. Blood samples for determination of gonadotrophins, prolactin (Prl), oestradiol (E2), progesterone, thyroid hormones and thyrotrophin in radioimmunoassays were taken and a combined TRF and LRF test carried out in the follicular phase before treatment, at the 6th month of treatment and after reappearance of the first menses. There were no statistically significant changes in the basal levels of serum FSH, LH or TSH during the danazol treatment. Neither was there any change in episodic secretions of FSH, LH or Prl, as determined by the mean coefficients of variation of the hormone levels in seven consecutive samples taken at 20 min intervals. On the other hand, serum E2, Prl and thyroid hormone levels were significantly decreased in the 6th month of treatment. In the TRF-LRF test the responses of serum FSH and LH were significantly higher and those of serum Prl and TSH significantly lower during danazol treatment than before. Prl responses remained lowered after the treatment. It appears that low serum oestrogen levels, induced by the danazol treatment, sensitize the pituitary gonadotrophs to exogenous LRF, but make the sensitivity of thyrotrophs and lactotrophs lower to exogenous TRF. These results thus indicate that danazol does not make the pituitary gonadotrophs insensitive to LRF, but danazol may rather inhibit the secretion of hypothalamic LRF.

scholarly journals LOWER BOUNDS OF CHARACTERISTIC SCALE OF TOPOLOGICAL MODIFICATION OF THE NEWTONIAN GRAVITATION

2012 ◽  
Vol 21 (05) ◽  
pp. 1250048
Author(s):  
L. IORIO
Keyword(s):  
Semimajor Axis ◽  
Data Sets ◽  
Orbital Elements ◽  
Dynamical Models ◽  
Spatial Direction ◽  
Newtonian Gravitation ◽  
Complementary Approach ◽  
Local Modification

We analytically work out the long-term orbital perturbations induced by the leading order of perturbing potential arising from the local modification of the Newton's inverse square law due to a topology ℝ2 × 𝕊1 with a compactified dimension of radius R recently proposed by Floratos and Leontaris. We neither restrict to any specific spatial direction [Formula: see text] for the asymmetry axis nor to particular orbital configurations of the test particle. Thus, our results are quite general. Nonvanishing long-term variations occur for all the usual osculating Keplerian orbital elements, apart from the semimajor axis which is left unaffected. By using recent improvements in the determination of the orbital motion of Saturn from Cassini data, we preliminarily inferred R ≳ 4-6 kau . As a complementary approach, the putative topological effects should be explicitly modeled and solved-for with a modified version of the ephemerides dynamical models with which the same data sets should be reprocessed.

ANALISA LOGAM BESI (Fe) DI SUNGAI PASAR DAERAH BELANGWETAN KLATEN DENGAN METODE SPEKTROFOTOMETRI SERAPAN ATOM

2017 ◽  
Vol 2 (1) ◽  
pp. 39
Author(s):  
Rahmi Nurhaini ◽  
Arief Affandi
Keyword(s):  
Heavy Metals ◽  
Sampling Method ◽  
Research Result ◽  
The Body ◽  
Clean Water ◽  
Observational Method ◽  
The Mean ◽  
The Republic

Iron (Fe) is one of many heavy metals that is corrosive resistant, dense, and has a low melting point. If accumulated in the body, the metal can cause some medical conditions, such as irritation to skin and eyes, breathing problems, and in the long term, cancer. This research aims to know generally the spread of metallic iron (Fe) in the river Pasar in Belangwetan, Klaten. This study was conducted using an observational method in which researchers did not examine the effects of interventions. Sampling was done using purposive sampling method taken from three points, namely the upper, middle, lower. Determination of iron levels by Atomic Absorption Spectrophotometer (AAS) obtained a positive result, and the data was processed using SPSS to determine the Mean and Standard Deviation. Of the research result, it could be known the Mean score was 2.33 ppm and SD was 0.0352. The result of this research indicated that the levels of iron in the river Pasar in Belangwetan were 2.33 ppm. It means that the levels violate the regulation of the Minister of Health of the Republic of Indonesia, which is not more than 1mg/L (1ppm) in the clean water

scholarly journals The orbital evolution of meteor streams at the 2/1 resonance with Jupiter

1985 ◽  
Vol 83 ◽  
pp. 179-180
Author(s):  
Cl. Froeschlé
Keyword(s):  
Major Axis ◽  
Orbital Evolution ◽  
The Sun ◽  
Orbital Elements ◽  
Meteor Stream ◽  
Semi Major Axis ◽  
Meteor Streams ◽  
Gravitational Forces ◽  
Resonant Effect

We investigated the orbital evolution of Quadrantid-like meteor streams situated in the vicinity of the 2/1 resonance with Jupiter. For the starting orbital elements we took the values of the orbital elements of the Quadrantid meteor stream except for the semi-major axis which was varied between a = 3.22 and a = 3.34 AU. We considered these meteor streams as a ring and we investigated the resonant effect on the dispersion of this ring over a period of 13 000 years. Only gravitational forces due to the Sun and due to Jupiter were taken into account.

Reachable domain of spacecraft with a single normal impulse

2019 ◽  
Vol 91 (7) ◽  
pp. 977-986 ◽  
Author(s):  
Junhua Zhang ◽  
Jianping Yuan ◽  
Wei Wang ◽  
Jiao Wang
Keyword(s):  
Major Axis ◽  
Emergency Evacuation ◽  
Semi Major Axis ◽  
Content Type ◽  
Orbital Transfers ◽  
Ellipsoid Of Revolution ◽  
Rendezvous And Docking ◽  
Practical Implications ◽  
Initial Orbit

Purpose The purpose of this paper is to obtain the reachable domain (RD) for spacecraft with a single normal impulse while considering both time and impulse constraints. Design/methodology/approach The problem of RD is addressed in an analytical approach by analyzing for either the initial maneuver point or the impulse magnitude being arbitrary. The trajectories are considered lying in the intersection of a plane and an ellipsoid of revolution, whose family can be determined analytically. Moreover, the impulse and time constraints are considered while formulating the problem. The upper bound of impulse magnitude, “high consumption areas” and the change of semi-major axis and eccentricity are discussed. Findings The equations of RD with a single normal impulse are analytically obtained. The equations of three scenarios are obtained. If normal impulse is too large, the RD cannot be obtained. The change of the semi-major axis and eccentricity with large normal impulse is more obvious. For long-term missions, the change of semi-major axis and eccentricity leaded by multiple normal impulses should be considered. Practical implications The RD gives the pre-defined region (all positions accessible) for a spacecraft under a given initial orbit and a normal impulse with certain magnitude. Originality/value The RD for spacecraft with normal impulse can be used for non-coplanar orbital transfers, emergency evacuation after failure of rendezvous and docking and collision avoidance.

Using spacecraft range data and radar observations for the improvement of the orbital elements of planets and parameters of Mars rotation

1996 ◽  
Vol 172 ◽  
pp. 45-48
Author(s):  
E.V. Pitjeva
Keyword(s):  
Major Axis ◽  
Astronomical Unit ◽  
Range Data ◽  
Orbital Elements ◽  
Semi Major Axis ◽  
The Earth ◽  
Electromagnetic Signals ◽  
Least Squares Estimates ◽  
Radar Ranging ◽  
Made In

The extremely precise Viking (1972–1982) and Mariner data (1971–1972) were processed simultaneously with the radar-ranging observations of Mars made in Goldstone, Haystack and Arecibo in 1971–1973 for the improvement of the orbital elements of Mars and Earth and parameters of Mars rotation. Reduction of measurements included relativistic corrections, effects of propagation of electromagnetic signals in the Earth troposphere and in the solar corona, corrections for topography of the Mars surface. The precision of the least squares estimates is rather high, for example formal standard deviations of semi-major axis of Mars and Earth and the Astronomical Unit were 1–2 m.

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