Results of the IMO Video Meteor Network - May 2008
==================================================

Up to now, May was the month were we had recorded least meteors. Between 1993 
and 2007, only 10,002 shooting stars were captured by our video network. That 
picture has changed, however, thanks to the exceptional weather this year. In 
the first half of May, there were essentially clear skies at each observing 
site. We have nine cameras that could observe in 13 or more of the first 15 
May nights. 
The weather changed rapidly in the second half of the month, when we had the
typical mix of clouds and rain, but overall we recorded more than 3500 meteors
in more than 1500 hours of effective observing time. That's about twice as 
many observing hours and two third more meteors as in 2007, the best year so 
far. Hence, May has now overtaken June, from which we have 11,680 records in 
the video meteor database. It remains to see, how the distribution looks like 
after the next month. 

With the eta-Aquariids there is a major shower early May, which, however, is
difficult to observe from northern latitudes where most cameras are located.
So it is no surprise that the following minor shower of the eta-Lyrids seemed
to have about the same activity. This impression is supported by an analysis,
where the number of shower meteors is summed up for each night and normalized
by the number of sporadics in the same night. The eta-Aquariids show an
activity profile with a broad maximum between May 4 and May 9 (figure 1). At
maximum their count was about a quarter of the sporadic count. The profile of
the eta-Lyrids has a more compact maximum between May 9 and May 11, where
they also reach about a quarter of the sporadic count.


Figure 1: Activity profiles of the eta-Aquariids, eta-Lyrids, and the
Antihelion source in the first half of May.

Which influence does the observing geometry have? The observability function
(that is the integral over the sine of the radiant altitude in the course of
the night) of the showers for a mean latitude of 48 deg N yields an
observation probability of about 5% for the eta-Aquariids, 31% for the
Antihelion source, and 74% for the eta-Lyrids. That reflects, that the
eta-Aquariids radiant rises only at dawn, whereas the radiant of the
eta-Lyrids in high up in the sky all night long. If we now set the maximum
ZHR of the eta-Aquariids to 50, we get a corrected average ZHR estimates of
the Antihelion source below 20, and a peak eta-Lyrids ZHR estimate of
about 3. That's much closer to the expected values.


1. Observers
============

Code    Name        Place           Camera         FOV    LM Nights Time Meteors
--------------------------------------------------------------------------------
BENOR Benitez-S.  Las Palmas    TIMES4 (1.4/50)   20 dg  3 mag  3    1.1 h     5
                                TIMES5 (0.95/50)  10 dg  3 mag  2    0.3 h     2
BRIBE Brinkmann   Herne         HERMINE (0.8/6)   55 dg  3 mag 22  106.7 h   162
CASFL Castellani  Monte Baldo   BMH1 (0.8/6)      55 dg  3 mag 17   52.5 h   102
                                BMH2 (0.8/6)      55 dg  3 mag  9   24.2 h    35
CRIST Crivello    Valbrevenna   STG38 (0.8/3.8)   80 dg  3 mag  2   12.9 h    20
ELTMA Eltri       Venezia       MET38 (0.8/3.8)   80 dg  3 mag  3   20.1 h    61
GONRU Goncalves   Tomar         TEMPLAR1(0.8/3.8) 80 dg  3 mag 12   62.4 h    72
HERCA Hergenroth. Tucson        SALSA (1.2/4)     80 dg  3 mag 22  151.2 h   191
HINWO Hinz        Brannenburg   AKM2 (0.85/25)    32 dg  6 mag 18   84.4 h   206
KACJA Kac         Kostanjevec   METKA (0.8/8)     42 dg  4 mag 15   75.5 h   127
                  Kamnik        REZIKA (0.8/6)    55 dg  3 mag  6   36.5 h    98
                  Ljubljana     ORION1 (0.8/8)    42 dg  4 mag 20   82.4 h   124
KOSDE Koschny     Noordwijkerh. ICC4 (0.85/25)    25 dg  5 mag 10   40.9 h    83
LUNRO Lunsford    Chula Vista   BOCAM (1.4/50)    60 dg  6 mag 14   64.7 h   270
MOLSI Molau       Seysdorf      AVIS2 (1.4/50)    60 dg  6 mag 15   80.8 h   739
                                MINCAM1 (0.8/6)   55 dg  3 mag 19  103.7 h   162
                  Ketzuer       REMO1 (0.8/3.8)   80 dg  3 mag 21  112.0 h   176
                                REMO2 (0.8/3.8)   80 dg  3 mag  6   24.6 h    69
PRZDA Przewozny   Berlin        ARMEFA (0.8/6)    55 dg  3 mag 14   79.1 h   156
SLAST Slavec      Ljubljana     KAYAK1 (1.8/28)   50 dg  4 mag 14   52.5 h    87
STOEN Stomeo      Scorze        MIN38 (0.8/3.8)   80 dg  3 mag 11   54.2 h   152
STRJO Strunk      Herford       MINCAM2 (0.8/6)   55 dg  3 mag 24   60.7 h    89
                                MINCAM3 (0.8/8)   42 dg  4 mag 17   39.0 h    63
                                MINCAM5 (0.8/6)   55 dg  3 mag 20   82.7 h   165
WEBMI Weber       Chouzava      TOMIL (1.4/50)    50 dg  6 mag  4    5.6 h    86
YRJIL Yrjola      Kuusankoski   FINEXCAM (0.8/6)  55 dg  3 mag 18   52.4 h    62
--------------------------------------------------------------------------------
Sum                                                            31 1563.5 h  3564


2. Observing Times (h)
======================

May    01   02   03   04   05   06   07   08   09   10   11   12   13   14   15
--------------------------------------------------------------------------------
BENOR   -    -   0.1   -    -    -    -    -   0.3   -    -    -    -    -   0.7
        -    -   0.2   -    -    -    -    -    -    -    -    -    -    -   0.1
BRIBE  2.4  2.5  7.7  1.1  7.6  7.5  7.4  7.4  7.3  7.2  7.2  7.1  2.3  2.0   -
CASFL   -   2.0  3.0   -   7.4   -    -   2.8  7.2  0.5  6.4  2.4  5.0  4.4  1.3
        -   1.0   -    -    -    -    -    -    -    -    -    -   3.3  4.2  3.9
CRIST  5.5  7.4   -    -    -    -    -    -    -    -    -    -    -    -    -
ELTRI   -    -    -    -   6.4   -    -   7.2   -    -    -    -   6.5   -    -
GONRU  8.2   -    -   7.7   -   5.3  3.9  7.9  3.7  2.5   -    -    -    -    -
HERCA  3.8  8.8  8.7  4.7  8.7  8.6  7.0  5.6  1.6  8.5  7.4  8.5  8.4  8.4  5.0
HINWO  5.3   -   2.7  6.6  1.5  3.9  6.5  6.4  6.3  6.3  6.2  6.1  6.1  4.5   -
KACJA  2.0  5.1  5.5  1.6   -    -   4.2  7.4   -    -   7.1  7.1  7.0  4.2  2.8
        -    -    -    -    -    -   6.1  4.3   -    -   4.9  7.1  7.2  6.9   - 
       1.1  5.8  0.8   -   1.6  5.3  2.4  6.4  3.2  5.3  7.3  6.3  6.2  5.1  1.3
KOSDE   -    -    -   5.6  5.9  4.3  2.8  5.1   -    -    -    -   2.2  1.0   -
LUNRO  2.3  7.5  8.5  2.0  2.5   -    -   3.4   -    -    -    -    -    -    -
MOLSI  6.0   -   5.4  6.5  5.8   -   5.7  6.2  5.5  6.1  4.2  5.9  5.7  5.9   - 
       5.0  2.6  4.4  2.3  7.2  7.2  7.1  7.1  7.0  6.9  6.9  6.8  6.8  5.2   -
       6.8  6.7  6.6  6.6  6.5  6.4  6.3  6.3  6.2   -   6.1  6.0  5.9  5.8  1.7
       4.8  2.3  3.6  5.6   -    -    -    -    -    -    -    -    -    -    -
PRZDA  2.7  6.8  6.7   -   6.5  6.5  6.4  6.3  6.2   -    -    -    -    -    -
SLAST   -   4.5  1.5   -    -   5.4  3.6  3.3   -   2.2  6.6  3.7  2.5  3.0   -
STOEN  6.5  7.3  1.4   -   7.3   -    -   4.7  5.4   -   0.9  6.3  6.9  1.4   -
STRJO  2.5  1.3  4.7  4.6  2.0  4.4  4.1  4.0  4.0  4.0  3.5  2.1  3.1  0.5   - 
       1.5  0.5  1.8  4.2  2.1  2.7  4.3  0.7  5.5  3.8  2.0  2.0  1.6   -    - 
       4.0  5.8  4.3  4.1  6.0  6.0  5.9  5.8  5.7  5.2  5.5  4.3  2.6   -    -
WEBMI   -    -    -    -   1.4  1.4  1.4  1.4   -    -    -    -    -    -    -
YRJIL   -   3.8  3.7  3.3  3.7   -   3.0   -   2.5  2.6  2.6  3.3   -   2.4  3.2
--------------------------------------------------------------------------------
Sum   70.4 81.7 81.3 66.5 90.1 74.9 88.1109.7 77.6 61.1 84.8 85.0 89.3 64.9 20.0
    
May    16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31
-------------------------------------------------------------------------------------
BENOR   -    -    -    -    -    -    -    -    -    -    -    -    -    -    -    - 
        -    -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
BRIBE  0.3   -   1.0  6.7  6.8  6.6  1.8  6.5   -    -    -    -   0.3   -    -    -
CASFL   -    -   0.7   -    -    -    -    -    -    -   4.4  1.5  1.7  0.5   -   1.3
       2.8   -    -    -    -    -    -    -    -   1.4  2.4   -   1.0   -    -   4.2
CRIST   -    -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
ELTRI   -    -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
GONRU  6.3  4.4   -    -    -   2.6   -   2.5   -    -    -    -    -    -   7.4   -
HERCA  7.0  8.2  8.0  8.3  8.2  4.2  3.6   -    -    -    -    -    -    -    -    -
HINWO   -    -    -    -    -    -    -   5.5  1.5   -   5.2  1.1   -   3.1   -    -
KACJA   -    -    -    -    -    -    -    -   6.7   -    -   6.1   -   2.2   -   6.5
        -    -    -    -    -    -    -    -    -    -    -    -    -    -    -    - 
        -    -    -    -    -    -    -    -    -   4.7  5.5  4.6   -   4.5  3.6  1.4
KOSDE   -    -    -    -   5.8  5.5   -   2.7   -    -    -    -    -    -    -    -
LUNRO  2.0  7.5  4.8  7.5  1.7   -    -    -    -    -    -    -   3.1  4.7  7.2   -
MOLSI   -    -    -    -    -    -    -    -    -   2.4   -    -    -   4.7  4.8   - 
        -    -    -    -    -    -    -   6.2   -    -   2.1   -    -   6.0  6.0  0.9
       1.1   -   2.5  3.4  5.4  5.4   -   5.2  5.1   -    -    -    -    -    -    - 
        -    -    -    -    -    -    -   3.2  5.1   -    -    -    -    -    -    -
PRZDA   -    -    -   5.5   -   5.4   -    -   5.2  5.2   -    -    -    -   4.9  4.8
SLAST   -    -    -    -    -    -    -    -    -    -   3.5  3.1   -    -   4.1  5.5
STOEN   -    -    -    -    -    -    -    -    -    -    -   6.1   -    -    -    -
STRJO  0.5   -   1.5  3.0  2.4  0.9  2.7  2.7  0.7   -    -    -   0.5  1.0   -    -
        -    -    -   2.1   -    -   1.5  1.5  1.2   -    -    -    -    -    -    - 
        -    -   1.3  4.9  0.8  3.8  3.0  3.2  0.5   -    -    -    -    -    -    -
WEBMI   -    -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
YRJIL  2.9   -    -    -   2.4   -   2.5  2.6  2.9  2.8   -    -    -    -   2.2   -
-------------------------------------------------------------------------------------
Sum   22.9 20.1 19.8 41.4 33.5 34.4 15.1 41.8 28.9 16.5 23.1 22.5  6.6 26.7 40.2 24.6


3. Results (Meteors)
====================

May    01   02   03   04   05   06   07   08   09   10   11   12   13   14   15
--------------------------------------------------------------------------------
BENOR   -    -    1    -    -    -    -    -    2    -    -    -    -    -    2 
        -    -    1    -    -    -    -    -    -    -    -    -    -    -    1
BRIBE   5    8   13    4   10   12    8   16   12   10    6    7    4    3    -
CASFL   -    8    1    -    7    -    -    9   10    1   11    5   18   10    3 
        -    2    -    -    -    -    -    -    -    -    -    -    4    7    6
CRIST   9   11    -    -    -    -    -    -    -    -    -    -    -    -    -
ELTRI   -    -    -    -   26    -    -   20    -    -    -    -   15    -    -
GONRU   9    -    -    9    -    5    2   11    5    1    -    -    -    -    -
HERCA   6   11   11    8   15    9    9    7    4   10    8   11    6   10    8
HINWO   6    -   11   10    1   13   13   21   20   15   24   23   15    8    -
KACJA   5   13    7    2    -    -   10   17    -    -   14    9   13    4    2 
        -    -    -    -    -    -   17   18    -    -   18   16   16   13    - 
        1   11    2    -    2   11    3    9    7   12    9   12   12    4    1
KOSDE   -    -    -   12   10    7    4   19    -    -    -    -    4    2    -
LUNRO   7   16   23   22   27    -    -   69    -    -    -    -    -    -    -
MOLSI  53    -   46   71   49    -   60   73   64   70   51   48   51   31    - 
        8    3    5    8   11   16   10   10   17   11    7   12    8    5    - 
        6    5   12    6    5   11    7   16   21    -   11    6    8    9    3 
       15    5   17   15    -    -    -    -    -    -    -    -    -    -    -
PRZDA   8    7   10    -    9    9    5   23   16    -    -    -    -    -    -
SLAST   -   11    2    -    -   12    7    7    -    2    8   10    4    4    -
STOEN  16   17    1    -   22    -    -   19   17    -    2   22   19    2    -
STRJO   4    3    6    6    3    6    5    4    6    5    4    2    7    1    - 
        3    1    3    8    4    4    8    1    7    4    2    4    3    -    - 
        8   13    7   10   15   14    9   12   10   18    1   10    5    -    -
WEBMI   -    -    -    -   23   19   28   16    -    -    -    -    -    -    -
YRJIL   -    6    1    7    7    -    2    -    1    8    1    7    -    1    3
--------------------------------------------------------------------------------
Sum   169  151  180  198  246  148  207  397  219  167  177  204  212  114   29

May    16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31
-------------------------------------------------------------------------------------
BENOR   -    -    -    -    -    -    -    -    -    -    -    -    -    -    -    - 
        -    -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
BRIBE   1    -    3    7   13    6    3   10    -    -    -    -    1    -    -    -
CASFL   -    -    1    -    -    -    -    -    -    -    9    2    3    1    -    3 
        1    -    -    -    -    -    -    -    -    2    5    -    3    -    -    5
CRIST   -    -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
ELTRI   -    -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
GONRU   8    8    -    -    -    1    -    3    -    -    -    -    -    -   10    -
HERCA   9   12    8   11    9    5    4    -    -    -    -    -    -    -    -    -
HINWO   -    -    -    -    -    -    -   11    4    -    7    1    -    3    -    -
KACJA   -    -    -    -    -    -    -    -   11    -    -    8    -    2    -   10 
        -    -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
        -    -    -    -    -    -    -    -    -    4    6    6    -    5    5    2
KOSDE   -    -    -    -   12    9    -    4    -    -    -    -    -    -    -    -
LUNRO   4   26   19   14    2    -    -    -    -    -    -    -   11   10   20    -
MOLSI   -    -    -    -    -    -    -    -    -    8    -    -    -   30   34    - 
        -    -    -    -    -    -    -   11    -    -    1    -    -    9    7    3 
        3    -    4    4   11   10    -    7   11    -    -    -    -    -    -    - 
        -    -    -    -    -    -    -    5   12    -    -    -    -    -    -    -
PRZDA   -    -    -   10    -   10    -    -   14   14    -    -    -    -    6   15
SLAST   -    -    -    -    -    -    -    -    -    -    5    6    -    -    6    3
STOEN   -    -    -    -    -    -    -    -    -    -    -   15    -    -    -    -
STRJO   1    -    3    5    4    1    4    4    2    -    -    -    1    2    -    - 
        -    -    -    4    -    -    3    2    2    -    -    -    -    -    -    - 
        -    -    3    7    3    6    6    7    1    -    -    -    -    -    -    -
WEBMI   -    -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
YRJIL  10    -    -    -    1    -    1    3    1    1    -    -    -    -    1    -
-------------------------------------------------------------------------------------
Sum    37   46   41   62   55   48   21   67   58   29   33   38   19   62   89   41

Sirko Molau, 2008/06/20