From: RainerArlt, International Meteor Organization
Date: Thu, 20 Nov 2003 10:10:14 +0100 (CET)



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           I M O   S h o w e r   C i r c u l a r
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                    LEONIDS 2003, VISUAL


The 2003 Leonid meteor shower has not yet provided distinct
peaks of activity. A full week of moderate Leonid meteor
rates has shown only one clear maximum; near 2003 Nov 19.4 UT
with an uncertainty of roughly +-6 hours.

This maximum coincides with the predicted times of about
06h30 - 08h00 UT for the encounter with the 15-revolution
dust trail of parent comet 55P/Tempel-Tuttle. The dust
was ejected from the comet near its perihelion passagein
1533.

The material ejected in 1499 has produced enhanced rates
on November 13, but no clear peak time can be derived from
the data received so far.

The ZHR gives the number of meteors as if the radiant would
be in the zenith, and at an observer's stellar limiting
magnitude of +6.5. The latter condition implies strong
extrapolations of observed meteor numbers, since the waning
moon interfered with most of the observing periods.

At this preliminary state, only the relative variations in
the ZHR should be of interest. Absolute values must be
discussed and fixed with the full dataset.

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Date     Solarlong  nINT   nLEO    ZHR
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Nov 12.80   229.93     1      0     (0)
Nov 13.50   230.64     4     13     26
Nov 13.72   230.86     7     12     21
Nov 14.01   231.15     7      9     27
Nov 14.77   231.92     1      2    (47)
Nov 15.76   232.91    13     28     15
Nov 16.24   233.40     1      4    (20)
Nov 17.21   234.37     4      7      7
Nov 18.52   235.69     6     18     13
Nov 19.06   236.24     9     63     23
Nov 19.14   236.32    10     51     39
Nov 19.37   236.55    14     88     53
Nov 19.90   237.09    14     35     39
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A population index of r=2.3 was used to extrapolate to lm=+6.5.
All solar longitudes refer to equinox J2000.0. nINT is the
number of observing periods, nLEO the number of Leonid meteors.

We would like to thank the following observers for their
contributions to the above ZHR table:

Alexandre Amorim, Joseph Assmus, Jure Atanackov, Aleksandar Atevik,
Shushrut Bhanushali, Michael Boschat, Dustin Brown, Ed Cannon,
Parag Deotare, Kshitija Deshpande, Lucio Furlanetto, Kearn Jones,
Paul Jones, Javor Kac, Ashish Kuvelkar, Anna Levina, Michael Linnolt,
Qiang Ma, Xiaoyun Ma, Paul Martsching, Mikhail Maslov, Alastair
McBeath, Norman McLeod, Huan Meng, Yatin Patnekar, Nilesh Puntambekar,
Tushar Purohit, Jurgen Rendtel, Rahul Sangole, Mikiya Sato, Tomoko
Sato, Vladimir Slusarenko, Wesley Stone, Kazumi Terakubo, Richard
Taibi, Michel Vandeputte, Jeremie Vaubaillon, Linjia Wang, Yi Wang,
Guangjie Wu, Quanzhi Ye, Chao Zhang, Menglin Zhang, Zhousheng Zhang.