(meteorobs) IMO Shower Circ.: First glance at Perseids

[RainerArlt]

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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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        The 2004 Perseids

Accoding to the below, very first analysis of the 2004
Perseids, the additional activity peak near 21h UT on
August 11, 2004, was confirmed by visual observations
sent to the IMO. Particle simulations predicted that this
peak is caused my material ejected from Comet Swift-Tuttle
at its perihelion passage in 1862 (1-revolution dust
trail).

There is not enough data yet to fix the time and level
of the traditional Perseid maximum expected for near 
10h UT on August 12. The peak time of the 1-rev dust trail
will probably be fixed with an accuracy of 10 minutes 
soon.

We are most grateful to the observers who have contributed
so far to the analysis (observing periods have been 
selected to get a reasonable coverage -- complete input
will be done in the next hours):

Rainer Arlt (Germany)
Roberto Bacci (Italy)
Lukas Bolz (Germany)
Michael Boschat (Canada)
Sietse Dijkstra (the Netherlands)
Audrius Dubietis (Lithuania)
Andre Knofel (Germany)
Dovile Kraulaidiene (Lithuania)
Ralf Kuschnik (Germany)
Marco Langbroek (the Netherlands)
Mike Linnolt (USA)
Robert Lunsford (USA)
Vladimir Lukic (USA)
Hartwig Luthen (Germany)
Felix A. Martinez (USA)
Sirko Molau (Germany)
Norman W. McLeod (USA)
Sven Nather (Germany)
Daniel van Os (the Netherlands)
Jurgen Rendtel (Germany)
Petra Rendtel (Germany)
Oliver Wusk (Germany)
Jurga Zieniute (Lithuania)

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Date (UT)   Time  Solarlong   nINT   nPER    ZHR
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Aug 11.35  08:24   138.943      6    137     37  +-  3
Aug 11.85  20:24   139.423     27    271    141  +-  9
Aug 11.87  20:53   139.443     19    174    185  +- 14
Aug 11.88  21:07   139.452     11    101    187  +- 19
Aug 11.89  21:22   139.462      8     30    131  +- 24
Aug 11.90  21:36   139.471     14     63     86  +- 11
Aug 11.91  21:50   139.481      8     16     48  +- 12
Aug 11.92  22:05   139.491      6     74     79  +-  9
Aug 11.96  23:02   139.529      9    136     87  +-  7
Aug 12.01  00:14   139.577     13    137     99  +-  8
Aug 12.04  00:58   139.606     20    236    126  +-  8
Aug 12.08  01:55   139.644     10    129    110  +- 10
Aug 12.26  06:14   139.817      4    151     59  +-  5
Aug 12.47  11:17   140.019      8     33    121  +- 21
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r = 2.0 was used. Solar longitudes refer to J2000.0


Rainer Arlt, 2004 Aug 12, 15h UT
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