(meteorobs) IMO Shower Circ.: Perseids 3rd analysis

[RainerArlt]

===============================================
   I M O     S H O W E R     C I R C U L A R
===============================================

   The 2004 Perseids, 3rd analysis

The peak time of the 1-revolution dust trail pre-
dicted by Lyytinen can now be narrowed down to the
period 20:55 UT to 21:05 UT. Since many observers
reported no details below 15-minute periods, it
will not be possible to be more precise.

The level of activity has increased compared with
the second analysis. We should bear in mind that
people were very much expecting something to happen,
and this can drive alertness beyond their average
observing behaviour. Care is due here.

This also leads us to the weakness of the peak in 
video data. A 10-minute breakdown of a video system
of Sirko Molau does show the peak. Numbers correct-
ed for radiant elevation and clouds is given below:

AVIS2 (90deg FOV, lm=6);
operated by Sirko Molau at Ketzuer, Germany;
corrected for clouds and hR
--------------------------
Period(UT)  N  Ncorr Cloud
--------------------------
2020-2030   3   12     50%
2030-2040   8   20     20%
2040-2050   7   18     20%
2050-2100   9   22     20%
2100-2110  16   30      0%
2110-2120   9   16      0%
2120-2130   4    9     20%
2130-2140   4    8     10%
2140-2150   5   10     10%
2150-2200   3    6     10%
2200-2210   3    6     10%
2210-2220   5    9     10%
2220-2230   4    8     20%
2230-2240   7   16     30%
2240-2250   4    7     10%
2250-2300  10   18     20%
2300-2310   4    6      0%
2310-2320   6    8      0%
[...]
--------------------------

This compares nicely with the period of ZHR>150 in the
below visual graph. The values are now based on about
750 observing periods.

------------------------------------------------------
Date (UT)   Time  Solarlong   nINT   nPER    ZHR
------------------------------------------------------
Aug 11.392  09:24   138.984     19    235     35  +-  2
Aug 11.726  17:25   139.304     26    193     68  +-  5
Aug 11.776  18:37   139.352     20    130     62  +-  5
Aug 11.833  19:60   139.407     18    125     91  +-  8
Aug 11.850  20:24   139.423     23    171    159  +- 12
Aug 11.860  20:38   139.433     27    241    146  +-  9
Aug 11.865  20:46   139.438     26    160    178  +- 14
Aug 11.872  20:56   139.445     30    297    196  +- 11
Aug 11.879  21:06   139.451     35    291    182  +- 11
Aug 11.886  21:16   139.458     28    156    118  +-  9
Aug 11.893  21:26   139.465     33    244    137  +-  9
Aug 11.900  21:36   139.471     27    211    117  +-  8
Aug 11.909  21:49   139.480     46    224     82  +-  5
Aug 11.927  22:15   139.497     44    379    103  +-  5
Aug 11.949  22:47   139.518     34    318     89  +-  5
Aug 11.969  23:15   139.538     40    442     96  +-  5
Aug 11.990  23:46   139.558     38    465    112  +-  5
Aug 12.012  00:17   139.579     27    304    101  +-  6
Aug 12.031  00:45   139.597     29    405    124  +-  6
Aug 12.052  01:15   139.617     30    454    132  +-  6
Aug 12.073  01:45   139.637     23    348    119  +-  6
Aug 12.098  02:21   139.661     14    220    146  +- 10
Aug 12.193  04:38   139.753     16    371     96  +-  5
Aug 12.342  08:12   139.896     23   1117    118  +-  4
Aug 12.495  11:53   140.043     16    105     94  +-  9
Aug 12.819  19:39   140.354     25    284    100  +-  6
Aug 12.749  17:59   140.287      5     90     77  +-  8
Aug 13.146  03:30   140.668      3     15     27  +-  7
------------------------------------------------------
r = 2.0 was assumed, solar longitudes refer to J2000.0.

Until now, the following observers contribute to 
the curve (I am working on...):

Maxim Andreev (Russia)
Rainer Arlt (Germany)
Morteza Azizi (Iran)
Roberto Bacci (Italy)
Lukas Bolz (Germany)
Michael Boschat (Canada)
Dustin Brown (USA)
Zolfaqar Daneshi (Iran)
Luigi D'Argliano (Italy)
Sietse Dijkstra (the Netherlands)
Audrius Dubietis (Lithuania)
Shlomi Eini (Israel)
Li Feng (China)
Martin Galea de Giovanni (Malta)
Roberto Gorelli (Italy)
Daniel Grun (Germany)
Laszlo Gyarmati (Hungary)
Amir Hasanzadeh (Iran)
Takema Hashimoto (Japan)
Jan Hattenbach (Germany)
Kamil Hornoch (Czech Republic)
Yandong Hu (China)
Carl Johannink (the Netherlands)
Paul Jones (USA)
Roy Keeris (the Netherlands)
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)
Pierre Martin (Canada)
Antonio Martinez (Venezuela)
Felix A. Martinez (USA)
Mikhail Maslov (Russia)
Bruce McCurdy (Canada)
Huan Meng (China)
Sirko Molau (Germany)
Robert Morgan (USA)
Thom Morgan (USA)
Norman W. McLeod (USA)
Sven Nather (Germany)
Daniel van Os (the Netherlands)
Hamid Rakooy (Iran)
Jurgen Rendtel (Germany)
Petra Rendtel (Germany)
Marko Toivonen (Finland)
Shigeo Uchiyama (Japan)
Wei Wang (China)
Oliver Wusk (Germany)
Jiaqing Yang (China)
Joseph Zammit (Malta)
Xu Zhang (China)
Hao Zheng (China)
Jurga Zieniute (Lithuania)
Vladimir Znojil (Czech Republic)


Rainer Arlt, 2004 August 14, 14h UT
-----------------------------------