Detailed visual observations and modelling of the 1998 Leonid shower |
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Authors: | P Brown R Arlt |
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Institution: | Department of Physics and Astronomy, University of Western Ontario, London, Ontario, N6A 3K7 Canada;International Meteor Organization, PF 600118, D-14401 Potsdam, Germany |
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Abstract: | We present a detailed activity profile for the 1998 Leonid shower from visual observations. The shower displayed at least two distinct components – a broad component peaking between 234 4 and 235 0, and two narrower filaments near 235 21 and 235 33 probably of younger origin based on modelling results. This dual-peaked structure in the flux profile has peak fluxes to a limiting magnitude of +6.5 of 0.03 Leonid km?2 h?1. The distribution of particles also changes dramatically across the stream in 1998, with large meteoroids dominating the early peak and smaller meteoroids relatively more abundant near the time of the nodal passage of the comet. Detailed comparison of the observed activity with models in 1998 shows that the early component comes from material ejected between 500 and 1000 yr ago. Our modelling results suggest that the later dual peaks are caused by high- β meteoroids with large ejection velocities released during the 1932 and 1965 passages of Comet 55P/Tempel–Tuttle. |
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Keywords: | comets: individual: 55P/Tempel–Tuttle meteors meteoroids |
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