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            International Meteor Organization
                 Meteor Shower Circular

            2 0 0 1    L E O N I D S (UPDATE)
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While utilizing all the incoming data for a global analysis of the Leonid
meteor shower, an update on the activity graph may be of interest. We find
two main peaks of activity: between
November 18, 10h30m and 10h40m UT, a maximum with ZHR~1400 was observed.
Lyytinen et al. predicted 10h28m and achieved best agreement. The second
peak is located near November 18,
18h20m UT which is very close to the predicted times of Lyytinen et al.
(18h20m) and McNaught & Asher (18h13m). The Asian peak  is skew with a
longer anscending branch. This may indicate the  presence of activity from
the 9-revolution dust trail.

Compared with the first analysis by Krumov, the picture has essentially
remained the same. Now, higher-resolution Leonid bins are available from the
observers. The following 25 observers were included in the below analysis:

 Rastislav Bagin, Chu-lok Chan, Yeon-jong Choi, George W. Gliba,
 Lew Gramer, Pavol Habuda, Xiaolin Huang, Richard Huziak, Martin
 Krsek, Martin Lehky, Michael Linnolt, Robert Lunsford, Hartwig
 Luthen, Monika Martiniskova, Peter Martinisko, Norman McLeod,
 Huan Meng, Sirko Molau, Peter Mrazik, Andrzej Skoczewski, Roger
 Venable, Miroslav Vetrik, Barbara Wilson, Dan Xia, Zhou Xingming.

The selection is simply caused by the process of entering data into the
Visual Meteor Database; presence or absence of reports is not a measure of
quality. Please do not complain your report
is missing here -- hundreds of reports are actually missing as yet!

For the first time, a profile of the population index was computed. It
covers the Asian peak and shows a significant increase of r during the peak.
The population index was near 2.0 before and after the Asian peak. It may
have been even lower for other periods which have not been covered, given
the large number of bright meteors reported. 

--------------------------------------------
Sollong   NINT   ZHR  error   r   Date/Time
(J2000)
--------------------------------------------
233.6803   6    10.7   2.4  2.00
234.8489  16    16.9   1.7  2.00
235.6417  23    33.6   2.4  2.00
235.7577  18    56.0   4.2  2.00
235.7948  17    72.4   5.2  2.00
235.8300  14    92.0   6.6  2.00
235.8681  14    86.3   6.1  2.00
236.0146  10   141.2  10.1  2.00
236.0442   8   198.7  16.8  2.00
236.0648   9   239.7  18.2  2.00
236.0791   4   312.4  23.4  2.00
236.0873   2   417.9  57.4  2.00
236.0936   6   474.7  34.6  2.00
236.1007   5   641.8  47.6  2.00
236.1090   8   664.1  49.0  2.00
236.1136  12   738.2  55.6  2.00
236.1177  13   691.3  48.9  2.00
236.1217   9   968.3  77.8  2.00
236.1249  10  1241.3 103.4  2.00  Nov 18 1021
236.1282  14  1067.0  77.8  2.00  Nov 18 1026
236.1308  11  1429.3 105.9  2.00  Nov 18 1030
236.1326  11  1032.8  87.0  2.00  Nov 18 1032
236.1348  12  1118.3  89.5  2.00  Nov 18 1035
236.1371  12  1309.6  95.0  2.00  Nov 18 1039
236.1389   9  1284.7 112.2  2.00  Nov 18 1041
236.1408  13  1160.3  86.0  2.00  Nov 18 1044
236.1435  15  1144.5  82.4  2.00  Nov 18 1048
236.1461  13  1006.6  76.8  2.00  Nov 18 1052
236.1495  13   829.9  64.6  2.00
236.1619  10   780.6  55.6  2.00
236.1725  16   735.6  56.9  2.00
236.1871   9   473.9  34.2  2.00
236.2458   8   319.7  22.9  2.00
236.3029   7   371.3  27.1  2.00
236.3256   6   397.6  29.5  2.00
236.3499   9   369.5  35.7  2.01
236.3797  36   507.6  27.1  2.02
236.3975  48   741.1  37.1  2.03
236.4073  45   903.8  46.4  2.03
236.4152  32  1239.2  62.8  2.04
236.4205  27  1321.2  71.1  2.04
236.4251  23  1503.8  76.0  2.05
236.4299  26  1280.1  69.2  2.05
236.4345  19  1753.5  88.5  2.08  Nov 18 1743
236.4386  17  1651.6  87.4  2.11  Nov 18 1749
236.4422  14  1848.2 103.2  2.15  Nov 18 1754
236.4457  14  2057.9 110.2  2.17  Nov 18 1759
236.4484  10  2242.5 130.6  2.17  Nov 18 1803
236.4515  18  1861.9  94.2  2.17  Nov 18 1807
236.4541  11  2112.8 125.4  2.17  Nov 18 1811
236.4561   9  2406.9 121.6  2.17  Nov 18 1814
236.4582   7  2196.5 150.5  2.16  Nov 18 1817
236.4600  10  2630.0 140.8  2.15  Nov 18 1820
236.4621  11  2192.9 121.6  2.15  Nov 18 1823
236.4644  12  1906.7 102.4  2.14  Nov 18 1826
236.4668  13  2370.8 120.2  2.15  Nov 18 1829
236.4690   9  2400.5 137.5  2.17  Nov 18 1832
236.4712  11  1958.0 109.6  2.20  Nov 18 1836
236.4739  13  2160.8 112.8  2.21  Nov 18 1839
236.4765  12  1656.7  93.3  2.18  Nov 18 1843
236.4798  16  1416.5  70.8  2.15  Nov 18 1848
236.4846  13  1482.9  77.9  2.10  Nov 18 1855
236.4882  14  1448.3  73.6  2.07  Nov 18 1900
236.4932  21  1051.6  52.6  2.03
236.4978  19  1222.4  63.0  2.01
236.5034  22  1108.2  55.8  1.99
236.5123  22  1087.2  55.6  1.96
236.5207  29   848.3  42.8  1.92
236.5317  31   759.0  38.7  1.90
236.5465  32   635.8  32.7  1.92
236.6595  40   208.6  10.7  1.96
--------------------------------------------

NINT is the number observing periods involved. We used the population index
given in the last column, the zenithal exponent is 1.0. Averaging periods do
not overlap; each period is used only once. Errors are the +-ZHR/sqrt(n)
margins of the Leonid number n.

Rainer Arlt, 2001 November 26.

Last Revised: 2001 November 29th
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