Prediction of meteoroid stream structure based on meteoroid fragmentation
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J. Astrophys. Astr. (2020) 41:25 https://doi.org/10.1007/s12036-020-09639-6
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Prediction of meteoroid stream structure based on meteoroid fragmentation K. SANJEEV KUMAR1,*, N. RAKESH CHANDRA2, G. YELLAIAH1
and B. PREM KUMAR1 1
Department of Astronomy, Osmania University, Amberpet 500 007, India. Department of Physics, Aurora Engineering College, Bhongir 500 095, India. *Corresponding author. E-mail: [email protected] 2
MS received 8 January 2020; accepted 18 July 2020 Abstract. Every day, large number of meteoroids enter the Earth’s atmosphere and deposit their mass either in atomic form or in ionic form depending on whether it has undergone ablation or fragmentation. The heavier meteoroids undergo fragmentation while the lighter ones are more prone to ablate. In this paper, we would like to speculate meteoroid stream structure of Leonid meteor shower based on fragmenting meteoroids. A 23 revolutions old meteoroid trail left behind by the comet 55P/Tempel-Tuttle in the year 1213 AD, which instigated Leonid meteor shower in the year 2010 is considered for our study. We have calculated mass of the meteoroids, echo durations and percentage of fragmentation. From the observed echo durations of meteoroids, estimated masses and from the percentage of fragmentation, we visualize the stream structure to be like the lighter particles wrapping up the heavier ones. The results we draw from these three different studies are matching with each other. To our knowledge, we are the first to speculate on the meteor stream structure based on fragmentation and making it a new tool in meteor stream evolution. Based on echo durations, it has been observed that 72% of the activity during the shower is contributed by lighter particles of the stream. It is found that about 20% of the meteoroids have undergone fragmentation indicating the minimal role of heavier particles ([106 g) during Leonid Meteor Shower (LMS). The masses of the meteors are estimated to be in the range of 1010 –105 g. Keyword. Meteor—meteor shower—fragmentation.
1. Introduction Every day, a large number of meteoroids ablate in the Earth’s atmosphere. When the comet is around its perihelion, meteoroids are ejected by the comet as its frozen ices sublimate under the heat of the Sun. The momentum transfer of the gases expanding away from the nucleus must be enough to overcome the gravity of the nucleus for meteoroids to escape a comet (Whipple 1951). Both of these forces, gas drag and gravity, increase with the size of the nucleus assuming other parameters to be constant. The gas drag is more important except for large meteoroids or extremely big comets (Whipple 1951). The path of the meteoroid around the Sun is elliptical with the Sun at one of the foci. A meteoroid stream is formed when the ejected meteoroids complete one orbit around the Sun.
Initially, meteoroids hang around the comet nucleus as a dust cloud, called the dust coma. Such meteoroids define a ‘trail center’ and the calculations tell us by how m
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