The activity of the 2004 Geminid meteor shower from global visual observations |
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Authors: | R Arlt J Rendtel |
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Institution: | International Meteor Organization, PF 600118, D-14401 Potsdam, Germany;Astrophysikalisches Institut Potsdam, An der Sternwarte 16, D-14482 Potsdam, Germany |
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Abstract: | A comprehensive set of 612 h of visual meteor observations with a total of 29 077 Geminid meteors detected was analysed. The shower activity is measured in terms of the Zenithal Hourly Rate (ZHR). Two peaks are found at solar longitudes and with ZHR = 126 ± 4 and ZHR = 134 ± 4 , respectively. The physical quantities of the Geminid meteoroid stream are the mass index and the spatial number density of particles. We find a mass index of s ≈ 1.7 and two peaks of spatial number density 234 ± 36 and 220 ± 31 particles causing meteors of magnitude +6.5 and brighter in a volume of 109 km3, for the two corresponding ZHR maxima. There were 0.88 ± 0.08 and 0.98 ± 0.08 particles with masses of 1 g or more in the same volume during the two ZHR peaks. The second of the two maxima was populated by larger particles than the first one. We compare the activity and mass index profiles with recent Geminid stream modelling. The comparison may be useful to calibrate the numerical models. |
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Keywords: | meteors meteoroids |
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