[IAUC] CBET 2046: 20091124 : LEONID METEORS 2009

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                                                  Electronic Telegram No. 2046
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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LEONID METEORS 2009
     P. Jenniskens, SETI Institute; and J. Vaubaillon and P. Atreya, IMCCE,
Paris, observing from the National Observatory of Nepal, report that the
Leonid shower (cf. CBET 2019) did show enhanced rates.  In a 40-min clear-sky
interval centered at Nov. 17d23h25m UT, the Leonid rate was ZHR = 56 +/- 16
meteors.  G. Barentsen, International Meteor Organization, analysed 3756
visually observed Leonids by 107 observers; from 1670 Leonids observed under
sky limiting magnitudes in excess of 5.0, he found an average population
index of chi = 1.9 +/- 0.4.  Based on this, he calculated a peak activity of
ZHR = 101 +/- 8 at Nov. 17d20h19m +/- 8m UT, with a FWHM of 4 +/- 1 hr.
Alternatively, the reported rates can be interpreted as composed of a
1-day-wide filament component with peak ZHR = 25 +/- 5 meteors
(magnitude-distribution index chi = 1.9) at solar longitude 235.35 deg (Nov.
17d17h UT), and one or two narrow peaks centered on 235.50 +/- 0.01 deg and
235.67 +/- 0.03 deg (equinox 2000.0), with FWHM = 0.08 and 0.12 deg and peak
rates of ZHR = 60 and 20/hr.  Presumably, these were caused by the encounters
with the 1466 and 1533 dust trails of comet 55P/Tempel-Tuttle.


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                         (C) Copyright 2009 CBAT
2009 November 24                 (CBET 2046)              Daniel W. E. Green