The 2004 Perseids, 3rd analysis

The peak time of the 1-revolution dust trail predicted 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 corrected 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)