S318p.41 — Frequency analysis of distributions of near Earth asteroids semi-major axes

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Aug 4th at 6:00 PM until 7:30 PM




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Author(s): Yuriy Cherkas1, Yury Voloshchuk1, Svitlana Kolomiyets1

Institution(s): 1. Kharkiv national university of radioelectronics

Hypotheses that the space of possible orbits in gravitational systems is discrete long have been the subject of study. Discreteness of the orbit space, if it exists, should primarily appear in their distribution over the semi-major axes. According to theories attempting to explain the discrete nature of distributions of orbits in the Solar system: the alternation of gaps and areas with concentrations of small bodies relative to their distribution of semi-major axes must have a certain order. Semi-major axis value in places of belts and gaps must be a multiple of the a0 – minimum commensurability value (fundamental harmonic), which characterize the gravitational system: ak=ka0/2 (where k – natural numbers).
As an object of study for this work are selected near Earth asteroids (NEA). In contrast to the main belt asteroids, in the first approximation we can assume that their movement is determined only by the gravitational influence of the Sun, and the sample size is sufficient to carry out the required analysis.
In general, the process of investigation can be summarized into following steps:
1) NEAs orbits data transformation – building of frequency histograms.
2) Histogram trend estimation and its elimination.
3) Frequency analysis of result series.
To eliminate misrepresentation of results, calculations were run for two different frequency histograms with number of intervals equal to 100 and 200. Analyzed range of semi-major axes was restricted with following values amin=0.5a.u. and amax=3.5a.u. Smoothing by fifth degree polynomial spline was chosen as a method of trend estimation (number of spline knots was an adjustable parameter). After removing of the estimated trend from frequency histograms, we got series of asteroids variation. Frequency representations of the series was obtained by calculation of periodograms.
Results of NEA’s orbits distributions fine structure investigation show that beside of systematic (trend) and sporadic (noise) components it contains periodical components. A harmonic on frequency f≈10.3a.u.-1 was detected with high level of significance.