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PhD. Topics

Astronomical Institute

Distribution of the orbits of sporadic meteoroids
PhD. program
Astronomy and Astrophysics
Name of the supervisor
RNDr. Mária Hajduková, PhD.
Receiving school
Faculty of Mathematics, Physics and Informatics
Affiliation: Astronomical Institute of the Slovak Academy of Sciences, The Department of Interplanetary Matter, Bratislava
Focus of the thesis: On its orbit around the Sun, the Earth crosses the orbits of a number of meteoroids, and, together with the whole solar system, passes through the interstellar medium. Thus, it collides with nearby particles which can be registered as meteors in the Earth’s atmosphere. Observations of the atmospheric trajectories of meteors lead us to their heliocentric orbits, on which meteoroids moved before their collision with the Earth. These indicate the origin of the meteoroids. We can identify specific parent bodies of meteoroid streams in the Solar system; we can classify sporadic meteoroids (whether they are cometary or asteroidal particles); and we may indicate the origin of meteoroids outside the Solar system. This thesis will focus on the origin of the largest population – sporadic meteoroids, which have lost their identity during their evolution (i.e. no similarity between their orbits and the orbit of their parent body or that of other meteoroids can be found).
Aim of the work: The aim of this work is to map the sporadic background, based on models and the synthesis of observations obtained by different techniques. Observations from Earth of the sporadic background (and its representation in a coordinate system centered at the Earth’s apex) have revealed six apparent sources in which enhanced meteor densities are observed: the so-called helion and antihelion sources, the northern and southern apex sources, and the northern and southern toroidal sources. The distribution of radiants is geometrically determined, but different types of comets or asteroids can be found associated with different regions of enhanced density.
However, the origin of the sporadic background has not been fully explained. Generally, the entire population of comets, as well as various types of asteroids, is considered to be the source. But there are a few specific comets that distribute significantly more particles to the near-Earth region than others. We will investigate these sources on the basis of statistical distributions of the orbital elements and compare them with the results of different models.
Moreover, in the search for a dominant source for given radiant densities, the result turns out to depend on the observation technique. Different techniques are differently sensitive to different particle masses; however, their synthesis will allow a more comprehensive view of the distribution of the sporadic background, including the study of its evolution. In this work, we use meteoroid orbits from various available meteor databases.
Requirements: programming, English
Research field: Dynamical evolution of small solar system bodies
[1] Ryabova, Galina O.; Asher, David J.; Campbell-Brown, Margaret J. (Eds.), Meteoroids: Sources of Meteors on Earth and Beyond, ISBN 9781108426718, Cambridge University Press, 2019 (vybrané kapitoly).
[2] Murray, C. D., Dermott, S. F. Solar system dynamics, Cambridge, UK: Cambridge University Press, ISBN 0-521-57295-9 (hc.), ISBN 0-521-57297-4, 1999 (vybrané kapitoly).
[3] Wiegert, Paul, Vaubaillon, Jeremie, Campbell-Brown, Margaret, A dynamical model of the sporadic meteoroid complexc, Icarus, Volume 201, Issue 1, p. 295-310, 2009.
[4] Li, Y., Zhou, Q., Urbina, J., Huang, T.Y., Sporadic micro/meteoroid source radiant distribution inferred from the Arecibo 430 MHz radar obsertvations, MNRAS 515, 2088-2098, 2022.

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