Results of the IMO Video Meteor Network - July 2009
===================================================

July 2009 was an outstanding month, that raised the bar of the camera network
still a bit higher. Let's start with our new observer Istvan Tepliczky, who
is the second Hungarian supporting the video network. His camera HUMOB has
not yet found a fixed observing site and was therefor operated at different
locations in July. Together with Istvan, we had 20 observers operating
34 cameras all together in July.

Next the weather should be mentioned, which was unusually good. In particular
our observers in southern Europe rarely suffered from clouded nights and,
thus, a total of 16 cameras obtained 20 or more observing nights. In the last
week of July, there was fine weather at almost every observing site with
close to 30 cameras active each night. Even though July is the month with the
second shortest nights in the northern hemisphere, we managed to obtain more
than 2,700 hours of effective observing time. That's not only the by far best
July result to date, but the second best monthly result in the full history
of the video network! Whereas the meteor counts remained low in the first
few days of July, there was a significant increase once the moon disappeared
in the middle of the month. Just as you get in mid-January the impression,
that meteor counts are cut half from one day to the next, it felt as if they
were doubling after mid-July. Beside the moon, the slowly raising Perseid
activity and the maximum of the southern delta-Aquariids were to blame for
this effect. On July 29, we recorded again more than 1,000 meteors in a
single night, and by the end of July more than 13,000 meteors in total were
obtained by the observers.

Once more, there were also outstanding events in the previous month. Enrico
Stomeo managed to record two blazing fireballs of visually estimated -11 mag
(recorded by MIN38 and NOA38) and -20 mag (recorded by MIN38, NOA38 and SCO38)
within two nights (figure 1). Such meteors are ways too bright for our cameras
with are tuned for sensitivity, which is why they are hard to analyse. Still,
at least a few points along their trajectory could be measured in both cases.


Figure 1: Two bright fireballs recorded by Enrico Stomeo. On top an ANT from
July 17, 2009, 00:46 UT, and on bottom an SDA from July 19, 2009, 01:59 UT.

Now let's have a closer look at the southern delta-Aquariids, the dominating
shower of the month. In our video database, they can be tracked from July 21
until well into September. However, the last radiant positions are quite
uncertain, which is why we defined the end date as August 23 (figure 2).


Figure 2: Radiant position of the southern delta-Aquariids from data of the
IMO Video Meteor Database.

The long term analysis of all data until 2008 shows a plateau of almost
constant activity at maximum between July 27 and 31 reaching a video rate
(comparable to the visual ZHR) of about 18. The highest value occurs on
July 30 (solar longitude 127 deg), thereafter the activity drops clearly but
can be detected at a low level for a long time (figure 3, red bars). For the
analysis of the 2009 data, the number of SDA (1325 in total) was divided by
the number of sporadics (4564 in total) to get an estimate of the shower
activity for each night (figure 3, green line). Both graphs match well, but
highest SDA activity in this years occurred already at the night of July
28/29.


Figure 3: Long-term activity profile of the southern delta-Aquariids
(red bars). The green line represents the ratio between SDA and SPO in
July 2009.

During the latest analysis of the southern delta-Aquariids we noted, that
the velocity of this shower was not constant but decreased slowly. I had
observed this effect already during earlier analyses of long-lasting meteor 
showers, but thought that to be systematic errors of our analysis method. 
This time we asked the network coordinator of the Japanese SonotaCo network, 
and to my surprise SonotaCo observed the same trend towards lower velocities 
in his SDA orbits obtained from double station data (figure 4). Even though 
the decrease is smaller than in the IMO data, the tendency is unequivocal. 
The same consensus was obtained for three other showers that we compared. 
So now we believe that this effect, for which we have first ideas but no 
consistent explanation yet, is real.


Figure 4: Meteor shower velocity v_inf of the southern delta-Aquariids and
the alpha-Capricornids over solar longitude.

By the end of July, the alpha-Capricornids reach their activity maximum
as well, but their peak video rate of 5 is significantly lower. Also this
shower has a plateau of almost constant maximum activity between July 23
and 28, with the largest value at the end of the period (solar longitude 
125 deg). The radiant position is well defined between July 11 and 
August 11 (figure 5).


Figure 5: Radiant position of the alpha-Capricornids from data of the
IMO Video Meteor Database.

The ratio between alpha-Capricornids (900 in total) and sporadics (8420
in total) confirms the late maximum on July 29 (figure 6). Hence, there
were two active southern showers in these nights, which is well reflected
in the radiant plots of some cameras. Figure 7 shows a section from the
corresponding plot of MIN38 on July 28/29.


Figure 6: Long-term activity profile of the alpha-Capricornids (red bars).
The green line shows the ratio between CAP and SPO in July 2009.


Figure 7: The radiant plot of MIN38 from July 28/29 shows the southern
delta-Aquariids radiant left and the alpha-Capricornids radiant right.

Last but not least it should be mentioned, that we observed a decreasing
velocity for the alpha-Capricornids as well. With -0.18 km/s per degree
solar longitude, the value was slightly smaller than for the southern
delta-Aquariids (figure 4).


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

Code    Name        Place           Camera         FOV    LM Nights Time Meteors
--------------------------------------------------------------------------------
BRIBE Brinkmann   Herne         HERMINE (0.8/6)   55 dg  3 mag 23   69.6 h   309
CASFL Castellani  Monte Baldo   BMH1 (0.8/6)      55 dg  3 mag  8   36.4 h   136
                                BMH2 (0.8/6)      55 dg  3 mag  9   47.8 h   218
CRIST Crivello    Valbrevenna   C3P8 (0.8/3.8)    80 dg  3 mag 27  138.9 h   750
                                STG38 (0.8/3.8)   80 dg  3 mag 10   54.4 h   224
ELTMA Eltri       Venezia       MET38 (0.8/3.8)   80 dg  3 mag 17   93.5 h   349
GONRU Goncalves   Tomar         TEMPLAR1 (0.8/6)  55 dg  3 mag 28  181.0 h  1075
                                TEMPLAR2 (0.8/6)  55 dg  3 mag 28  155.7 h   585
GOVMI Govedic     Sredisce      ORION2 (0.8/8)    42 dg  4 mag 28  139.7 h   946
HERCA Hergenroth. Tucson        SALSA (1.2/4)     80 dg  3 mag 23   75.1 h   148
                                SALSA2 (1.2/4)    80 dg  3 mag 23   86.7 h   225
HINWO Hinz        Brannenburg   AKM2 (0.85/25)    32 dg  6 mag 16   66.5 h   365
IGAAN Igaz        Hodmezova.    HUHOD (0.8/3.8)   80 dg  3 mag 12   85.2 h   434
JOBKL Jobse       Oostkapelle   BETSY2 (1.2/85)   25 dg  7 mag 13   55.8 h   335
KACJA Kac         Kostanjevec   METKA (0.8/8)     42 dg  4 mag 18   84.9 h   185
                  Ljubljana     ORION1 (0.8/8)    42 dg  4 mag 27  112.2 h   310
                  Kamnik        REZIKA (0.8/6)    55 dg  3 mag 11   42.1 h   265
                                STEFKA (0.8/3.8)  80 dg  3 mag  7   25.7 h    63
KOSDE Koschny     Noordwijkerh. TEC1 (1.4/12)     30 dg  4 mag 17   40.2 h    95
LUNRO Lunsford    Chula Vista   BOCAM (1.4/50)    60 dg  6 mag 25  118.5 h   641
MOLSI Molau       Seysdorf      AVIS2 (1.4/50)    60 dg  6 mag 20   67.6 h  1032
                                MINCAM1 (0.8/6)   55 dg  3 mag 26   96.9 h   405
                  Ketzuer       REMO1 (0.8/3.8)   80 dg  3 mag 23   80.8 h   203
                                REMO2 (0.8/3.8)   80 dg  3 mag 26   90.3 h   445
OCHPA Ochner      Albiano       ALBIANO (1.2/4.5) 68 dg  3 mag 17   74.1 h   171
SLAST Slavec      Ljubljana     KAYAK1 (1.8/28)   50 dg  4 mag 18   43.9 h    86
STOEN Stomeo      Scorze        MIN38 (0.8/3.8)   80 dg  3 mag 27  139.8 h  1047
                                NOA38 (0.8/3.8)   80 dg  3 mag 26  125.6 h   545
                                SCO38 (0.8/3.8)   80 dg  3 mag 27  142.9 h   896
STORO Stork       Ondrejov      OND1 (1.5/50)     55 dg  6 mag  2    9.4 h   232
STRJO Strunk      Herford       MINCAM2 (0.8/6)   55 dg  3 mag 14   37.5 h   115
                                MINCAM3 (0.8/8)   42 dg  4 mag  8   20.1 h    71
                                MINCAM5 (0.8/6)   55 dg  3 mag 12   35.0 h   185
TEPIS Tepliczky   Budapest      HUMOB (0.8/3.8)   80 dg  3 mag  6   33.6 h   295
--------------------------------------------------------------------------------
Overall                                                        31 2707.4 h 13485


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

July   01   02   03   04   05   06   07   08   09   10   11   12   13   14   15
--------------------------------------------------------------------------------
BRIBE  3.4  5.9  0.8  4.3   -   2.3   -   0.3  0.3   -    -   4.7  2.4  2.8  4.4
CASFL   -    -    -    -    -    -    -    -    -    -    -    -    -    -    - 
        -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
CRIST  2.0  4.3  3.7   -    -   2.4  3.2  4.3  3.7  6.5  3.5  2.0  5.6  6.5  6.6
        -    -    -   1.0   -    -    -    -    -    -   4.3   -    -    -    -
ELTMA   -    -    -    -    -    -    -    -    -    -    -   4.4   -   4.3   -
GONRU  2.7  7.1  6.1  7.0  5.4  6.1  7.0  7.3  3.8  2.3  6.2   -   7.3  7.3  7.3
       1.1  7.1  7.1  1.9  3.4  4.0  3.9  7.2  1.9  1.3  6.2   -   7.3  7.3  7.3
GOVMI  3.7  3.5  1.2  3.1  6.5  2.5  3.4  4.1  1.9  3.2  5.6  4.4   -   6.8  3.4
HERCA   -    -   2.4   -   5.4  2.9   -   2.1  0.9  1.0  4.5  3.7  1.2  1.5   - 
        -    -    -    -   5.4  2.9   -   2.1  2.9  1.0  4.5  4.7  4.2  5.5   -
HINWO  3.1  0.5   -   1.4   -    -    -    -    -    -   3.5   -   4.5  4.3  4.1
IGAAN   -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
JOBKL  3.8   -   4.1  4.1   -   2.2   -   4.5   -    -    -   5.8   -   4.7  5.3
KACJA   -    -    -   2.5  2.5   -    -   1.0   -    -   2.1  2.6  6.1  4.8   - 
       1.0  4.3   -   4.4   -   1.0   -   0.6   -   1.2  5.0  4.5  4.5  4.6  3.6
        -   5.3   -    -   3.4   -    -   1.7  1.0   -    -   3.3  2.0   -   3.3
        -   4.6   -    -   2.4   -    -    -    -    -    -   2.3   -    -    -
KOSDE   -   2.7   -   2.8  2.5   -    -    -    -    -    -   2.2  3.6  1.3  4.0
LUNRO   -   2.1  1.0  1.9  3.5  2.6  2.7  2.2  1.4  2.6  2.9  7.4  7.7  5.8  7.8
MOLSI  2.3  3.3   -   1.3   -    -    -   0.1   -    -   1.1   -   2.2  1.4  5.4
       5.6  1.6   -   3.7  3.7  0.9  1.0  1.8   -   2.9  3.4   -   3.9  1.9  1.1
       2.4  4.4  1.5  2.5  4.5  1.7   -    -    -   1.2  4.8   -   3.8  3.9  3.0
       4.4  4.5  2.9  1.0  4.5  1.0   -    -    -   1.2  4.8  0.4  4.9  5.0  2.5
OCHPA   -    -    -    -    -    -    -    -    -    -    -    -   2.1  5.2  7.3
SLAST  1.2  3.5   -   2.0  2.1   -    -   1.5   -    -   1.1  4.2   -   5.1  3.2
STOEN  5.0  3.5  2.2   -   3.9   -    -   5.2  4.1  4.5  4.1  5.3  3.2  6.5  6.4
       3.5  3.0  3.0   -   2.7   -    -   4.2  3.1  4.5  5.2  6.3  2.2  5.4  6.4
       4.0  4.0  2.7   -   2.3   -    -   6.1  3.2  4.4  5.1  6.3  3.3  5.4  6.4
STORO   -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
STRJO  2.4  1.9   -   3.0   -    -    -    -   3.1   -    -    -   1.7   -   3.2
        -    -    -    -    -    -   2.7   -    -    -    -    -    -    -   1.0
        -    -    -    -    -    -   1.0   -    -    -    -    -   3.1  2.0  2.0
TEPIS   -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
--------------------------------------------------------------------------------
Sum   51.6 77.1 38.7 47.9 64.1 32.5 24.9 56.3 31.3 37.8 77.9 74.5 86.8109.3105.0

July   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31
-------------------------------------------------------------------------------------
BRIBE  3.6   -   3.3  0.6   -   0.4   -    -   0.4  5.6  3.1  5.1  5.3  1.1  4.6  4.9
CASFL   -    -    -    -    -    -    -    -   3.3  2.8  6.8  3.9  4.4  6.0  4.5  4.7
        -    -    -    -    -   4.5  6.7  4.7  5.1  2.5  6.2  4.2  6.9  7.0   -    -
CRIST  6.7   -   5.6  3.5  2.3  6.9  6.9  4.9   -   7.0  7.1  7.1  7.2  7.2  7.2  5.0
        -    -   5.6  6.8  6.8  4.7  5.9  6.9  6.0  6.4   -    -    -    -    -    -
ELTMA  5.4   -   5.0  6.8  4.4  6.8  4.9  5.7  5.3  3.4  7.0  6.8  5.8  6.9  4.5  6.1
GONRU  7.3  7.4  7.5  5.5   -   4.2   -   7.6  7.5  7.7  7.7  7.7  7.8  7.8  7.3  5.1
       7.4  7.4  7.5  4.0   -   4.2   -   6.6  6.0  7.7  5.7  7.7  6.3  5.8  6.8  5.6
GOVMI  6.8  6.5  6.5  6.5  7.0  7.0  7.1  7.1   -   5.9  6.5  6.1  4.6  7.0   -   1.8
HERCA  2.9   -   2.0  1.1   -   1.6   -   0.5  0.5  1.0  2.1  8.4  8.4  7.8  6.4  6.8
       0.9   -   3.0  1.1  1.1  1.6  3.4   -   0.5  1.0  3.1  8.4  8.4  7.8  6.4  6.8
HINWO  5.4   -    -   1.3  5.6  5.7  5.4   -    -    -   5.2   -   6.0  5.5   -   5.0
IGAAN   -    -    -    -   7.2  7.2  7.3  6.8  7.3  7.4  7.4  7.4  7.5  7.0  7.1  5.6
JOBKL   -    -    -    -    -    -    -   4.5   -   5.3   -   4.4   -    -   5.6  1.5
KACJA  6.8   -    -   5.8  4.8  6.9  3.9  4.1   -   5.6  7.2  7.3   -   7.3   -   3.6
       6.7  4.6  2.7  6.7  4.3  3.9  4.4  5.9  0.8  7.0  6.5  7.2  4.2  6.7  2.5  3.4
       3.8   -    -    -    -   6.7  6.8   -    -   4.8   -    -    -    -    -    - 
       3.9   -    -    -    -   1.8  5.9   -    -   4.8   -    -    -    -    -    -
KOSDE  0.6  0.9   -    -   2.0  1.2   -   2.7  2.4  1.8   -   4.1   -    -   1.8  3.6
LUNRO  7.3  6.7  4.9  6.4  7.8  7.6  8.0  4.4   -   6.0   -    -    -    -   3.9  3.9
MOLSI  3.6   -    -   4.0  4.4  5.0  1.2   -    -   5.0  5.5  1.4  5.7  5.6  3.6  5.5
       6.2   -    -   5.3  5.8  5.4  1.5  4.0  1.0  6.6  6.6  1.8  6.7  6.8  1.8  5.9
       5.1   -    -   4.3  2.3   -   3.0  3.5  5.6  4.2  1.2   -   5.9  4.4  1.5  6.1
       5.1   -    -   0.3  3.9  0.3  5.5  4.5  4.1  5.6  3.2  1.3  5.9  5.9  1.5  6.1
OCHPA  6.3   -   2.1  4.3  3.2  2.2  4.3  6.5   -   6.6  2.2  5.6  2.2  5.6  3.4  5.0
SLAST  6.1  0.7   -    -    -    -    -    -    -   0.8  1.8  1.3  4.3  0.7  1.9  2.4
STOEN  5.4  1.0  6.5  6.6  6.6  4.0  6.6  6.6  5.9   -   6.9  6.9  7.0  6.8  4.7  4.4
       4.3   -   6.5  5.5  4.5  3.0  6.6  5.5  3.7   -   6.9  6.9  7.0  6.8  5.0  3.9
       6.5  1.4  6.5  6.5  6.7  4.5  6.5  6.6  4.3   -   6.9  6.9  7.0  6.8  5.7  6.9
STORO   -    -    -    -    -    -    -    -    -    -    -    -    -   4.3  5.1   -
STRJO  4.5   -   3.6  0.5  1.0   -    -    -    -   1.6   -    -   5.2   -   0.3  5.5
       1.7   -   0.7   -    -    -    -    -    -   0.7   -    -   5.2   -   2.7  5.4
       4.2   -   2.9  1.7   -    -    -    -    -   3.1  0.7   -   5.3   -   3.6  5.4
TEPIS   -    -    -    -    -    -    -    -    -   5.2  5.9  5.3  5.2  6.1  5.9   -
-------------------------------------------------------------------------------------
Sum  134.5 36.6 82.4 95.1 91.7107.3111.8109.6 69.7133.1129.4133.2155.4150.7115.3135.9


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

July   01   02   03   04   05   06   07   08   09   10   11   12   13   14   15
--------------------------------------------------------------------------------
BRIBE  11    7    3   15    -    6    -    1    2    -    -   14    9    9   27
CASFL   -    -    -    -    -    -    -    -    -    -    -    -    -    -    - 
        -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
CRIST   2   24   14    -    -    4    6   16   13   16   10   10   19   26   45 
        -    -    -    1    -    -    -    -    -    -   18    -    -    -    -
ELTMA   -    -    -    -    -    -    -    -    -    -    -   12    -    5    -
GONRU  12   29   39   21   33   23   35   27   12    7   36    -   33   53   47 
        2   27   21    8    9    7   13   17    3    3   21    -   21   40   29
GOVMI  10   15    5   17   27   24   13   21    2   13   16   15    -   27   14
HERCA   -    -    2    -    7    7    -    2    2    3    8    4    2    2    - 
        -    -    -    -    8    4    -    3    5    1    4   11    5    5    -
HINWO  16    1    -    4    -    -    -    -    -    -   20    -   12   13   16
IGAAN   -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
JOBKL  15    -   18   18    -    7    -   14    -    -    -   35    -   17   37
KACJA   -    -    -    6    6    -    -    1    -    -    2    7   10    7    - 
        1    6    -    7    -    1    -    1    -    1    9    8   11   11    5 
        -   29    -    -   24    -    -    2    2    -    -   15    7    -   21 
        -   10    -    -    5    -    -    -    -    -    -    7    -    -    -
KOSDE   -    5    -    6    5    -    -    -    -    -    -    7    8    4    9
LUNRO   -    3    3    5    7    4    3    3    2    4    7   32   40   19   39
MOLSI  35   20    -    4    -    -    -    1    -    -    4    -   20   10   40 
       10    4    -    5    8    1    2    3    -   12   18    -    9    3    2 
        5    8    3    5   15    7    -    -    -    3   11    -   16   14    6 
       10   16    7    4   17    5    -    -    -    4   13    1   28   20   10
OCHPA   -    -    -    -    -    -    -    -    -    -    -    -    3   16   14
SLAST   2    8    -    3    3    -    -    2    -    -    2    9    -    9    3
STOEN  22   18    4    -   19    -    -   20    7   31   21   35    9   34   37 
        7    6    5    -    5    -    -   10    3   15   15   24    4   18   22 
       14   15    6    -    6    -    -   24    9   43   22   41   11   18   35
STORO   -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
STRJO   3    3    -    4    -    -    -    -    8    -    -    -    5    -   12 
        -    -    -    -    -    -    6    -    -    -    -    -    -    -    5 
        -    -    -    -    -    -    5    -    -    -    -    -    6    5   12
TEPIS   -    -    -    -    -    -    -    -    -    -    -    -    -    -    -
-------------------------------------------------------------------------------
Sum   177  254  130  133  204  100   83  168   70  156  257  287  288  385  487

July   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31
-------------------------------------------------------------------------------------
BRIBE   8    -   12    3    -    2    -    -    3   24   14   34   20    5   40   40
CASFL   -    -    -    -    -    -    -    -   18   11   21   13   14   25   15   19 
        -    -    -    -    -   12   23   19   25   10   33   18   29   49    -    -
CRIST  25    -   36   15   19   18   23   20    -   42   67   70   73   54   44   39 
        -    -   36   31   25   14   15   37   18   29    -    -    -    -    -    -
ELTMA  17    -   15   16   10   12   17   17   18    8   39   36   33   42   30   22
GONRU  46   34   36   20    -   25    -   44   52   56   50   76   62   75   51   41 
       19   29   21   10    -   10    -   24   28   37   23   45   33   35   32   18
GOVMI  40   23   29   57   40   47   34   44    -   80   96   83   83   60    -   11
HERCA   3    -    2    3    -    2    -    1    1    1    5   12   12   28   16   23 
        1    -    3    3    4    3    7    -    1    2   11   35   21   29   23   36
HINWO  15    -    -    3   29   29   33    -    -    -   42    -   51   47    -   34
IGAAN   -    -    -    -   25   45   32   25   32   30   50   41   52   34   45   23
JOBKL   -    -    -    -    -    -    -   28    -   51    -   32    -    -   52   11
KACJA  13    -    -    8    9   14    7   10    -   12   16   30    -   19    -    8 
       20    9    4   20   12   13    9   17    1   23   21   29   31   19    3   18 
       32    -    -    -    -   39   35    -    -   59    -    -    -    -    -    - 
        8    -    -    -    -    4   10    -    -   19    -    -    -    -    -    -
KOSDE   1    3    -    -    2    3    -    4    6    6    -   12    -    -    5    9
LUNRO  30   41   16   17   37   37   30   12    -   21    -    -    -    -  129  100
MOLSI  59    -    -   67   69   86   11    -    -   85  136    4  114  119   31  117 
       22    -    -   18   20   19    3   31    5   38   45    3   42   43    5   34 
       21    -    -    8    6    -    5    7   23   19   14    -   43   13    4   46 
       34    -    -    1   14    4   23   13   18   26   12    4   50   38    8   65
OCHPA  11    -    7    8    6    3   13   12    -   11    3   13    7   16   14   14
SLAST  13    2    -    -    -    -    -    -    -    2    5    2   14    1    3    3
STOEN  48    1   45   46   46   30   34   53   49    -   83   78   81   94   56   46 
       21    -   30   24   16   15   19   28   24    -   46   42   45   44   38   19 
       31    3   56   55   33   32   23   48   37    -   68   61   47   77   38   43
STORO   -    -    -    -    -    -    -    -    -    -    -    -    -  149   83    -
STRJO  10    -    9    1    2    -    -    -    -    8    -    -   21    -    1   28 
        4    -    1    -    -    -    -    -    -    1    -    -   21    -   14   19 
       20    -   12    5    -    -    -    -    -   14    4    -   29    -   27   46
TEPIS   -    -    -    -    -    -    -    -    -   53   51   61   31   46   53    -
------------------------------------------------------------------------------------
Sum   572  145  370  439  424  518  406  494  359  778  955  834 1059 1161  860  932

Sirko Molau, 2009/09/04