(meteorobs) IMO Shower Circ.: 2nd Perseid profile

[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, 2nd analysis

As an update of the first preliminary analysis of
the 2004 Perseids based on visual observations,
this is a refined graph with almost 500 observing
periods.

The peak time of the 1-revolution dust trail pre-
dicted by Lyytinen can be narrowed down to the
period 20:45 UT to 21:10 UT. This encloses the
predicted time of 20:54 UT on August 11. A plateau-
like maximum of 20-25 minutes duration has not
changed anymore after adding the last 100 observing
periods. The activity level was ZHR=170.

The traditional maximum is not yet well covered.
The dip of ZHR=75 may not be significant since
systematical errors may exceed the given statistical
error greatly (very small number of observers). 

Until now, the following observers contribute to 
the curve (forgive me if you are missing; I am 
working on):

Rainer Arlt (Germany)
Roberto Bacci (Italy)
Lukas Bolz (Germany)
Michael Boschat (Canada)
Dustin Brown (USA)
Sietse Dijkstra (the Netherlands)
Audrius Dubietis (Lithuania)
Daniel Grun (Germany)
Amir Hasanzadeh (Iran)
Takema Hashimoto (Japan)
Jan Hattenbach (Germany)
Andre Knofel (Germany)
Dovile Kraulaidiene (Lithuania)
Ralf Kuschnik (Germany)
Marco Langbroek (the Netherlands)
Peter van Leuteren (the Netherlands)
Mike Linnolt (USA)
Robert Lunsford (USA)
Vladimir Lukic (USA)
Hartwig Luthen (Germany)
Christophe Marlot (France)
Felix A. Martinez (USA)
Mikhail Maslov (Russia)
Bruce McCurdy (Canada)
Huan Meng (China)
Sirko Molau (Germany)
Thom Morgan (USA)
Norman W. McLeod (USA)
Sven Nather (Germany)
Daniel van Os (the Netherlands)
Jurgen Rendtel (Germany)
Petra Rendtel (Germany)
Eini Shlomi (Israel)
Shigeo Uchiyama (Japan)
Oliver Wusk (Germany)
Jurga Zieniute (Lithuania)


-------------------------------------------------------
Date (UT)   Time  Solarlong   nINT   nPER    ZHR
-------------------------------------------------------
Aug 11.353  08:28   138.946      6    137     37  +-  3
Aug 11.723  17:21   139.301     10    120     86  +-  8
Aug 11.780  18:43   139.356     11     69     71  +-  8
Aug 11.834  20:01   139.408     12     69    122  +- 15
Aug 11.850  20:24   139.423     19    136    154  +- 13
Aug 11.860  20:38   139.433     18    139    128  +- 11
Aug 11.865  20:46   139.438     22    141    176  +- 15
Aug 11.872  20:56   139.445     20    146    165  +- 14
Aug 11.879  21:06   139.451     27    197    173  +- 12
Aug 11.886  21:16   139.458     22    112    118  +- 11
Aug 11.893  21:26   139.465     24    114    105  +- 10
Aug 11.900  21:36   139.471     18    129    105  +-  9
Aug 11.909  21:49   139.480     33    101     63  +-  6
Aug 11.928  22:16   139.498     28    218     81  +-  5
Aug 11.949  22:47   139.518     24    224     83  +-  6
Aug 11.969  23:15   139.538     29    348     95  +-  5
Aug 11.991  23:47   139.559     26    334    109  +-  6
Aug 12.012  00:17   139.579     19    219    103  +-  7
Aug 12.033  00:48   139.599     24    336    121  +-  7
Aug 12.053  01:16   139.618     20    304    132  +-  8
Aug 12.079  01:54   139.643     22    339    128  +-  7
Aug 12.210  05:02   139.769      8    123     75  +-  7
Aug 12.347  08:20   139.901     12    683    110  +-  4
Aug 12.495  11:53   140.043     11     88    103  +- 11
-------------------------------------------------------
r = 2.0 was assumed, solar longitudes refer to J2000.0.


Rainer Arlt, 2004 August 13, 13h UT
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