Results of the IMO Video Meteor Network - December 2007
=======================================================
The year 2007 finished with true meteor fireworks. The weather was less
co-operative than in 2006, so that the monthly totals summed to "only"
1,700 hours of observing time and nearly 9,800 meteors. That was sufficient,
though, to ensure the first place for 2007 in the annual statistics.
In the first December days weather was particularly good for a winter month,
but right in time for the Geminids the situation became worse. At the maximum
night December 12/13 it was better again, but there was hardly an observing
site with truly clear skies. Often the observation was hampered by cirrus
clouds or fog. Bob Lunsford was in the best position of all - he had moved
for three nights into the Californian desert with pristine skies. On
December 14/15 he broke all records by capturing over 700 meteors in eight
hours of observing time. That result was only topped during the Leonid
storms.
In subsequent nights, the weather allowed one or the other observation.
However, just in time for the eagerly awaited Ursid maximum it deteriorated
again and improved only slightly towards the end of the year.
Now for the highlights of the month. At first I would like to mention a
sporadic meteor of first magnitude that I captured on the morning of
December 14 at 4:14 UT. What's so special about it? It's the 100,000st
meteor that I observed by video and analysed with MetRec! Ok, to be perfectly
honest, the one shown here is meteor no. 99,999. The real jubilee meteor was
much less attractive. ;-)
Back to the real highlights of the last month. First of all, the Geminids
have to be mentioned. Contrary to the previous year, there was no single
camera in 2007 with permanently clear skies on December 13/14 and 14/15. For
that reason, the activity graph had to be combined from time intervals with
clear skies from the individual cameras. Unfortunately I could not use the
data sets of the image-intensified cameras AVIS2 and BOCAM. That was
particularly pity, because the American data would have extended to profile
quite a bit. However, whereas all the other Mintron and Watec cameras have
in the first order similar recordings properties, the two intensified cameras
record much more meteors. The meteor counts would have to be scaled down,
but the scaling factor is not easily determined.
The resulting activity profile from the other cameras shows rising Geminid
activity in the evening of December 13 until about midnight. From there on,
it stays at an high level until dawn, and by the evening of December 14 the
rates are falling again.
The second highlight of December were the Ursids, which were supposed to
show enhanced rates in 2007. Just days before the maximum, Peter Jenniskens,
Esko Lyytinen and other renowned outburst specialists published a paper in
WGN. They had studied the development of dust trails from the parent comet
8/P Tuttle in the last 2000 years. It was concluded, that on December 22
between 20 and 22 UT ZHRs between 40 and 80 could have been expected, much
more than the usual maximum rate of about 10. Already at previous returns
of the short periodic parent comet, the Ursids had occasionally shown
enhanced rates, which could be explained more or less well by the dust
trail simulations.
Unfortunately, the weather was hardly co-operative in the night in question,
and the full moon was high in the sky. So only three cameras (Mincam2,
Mincam3, Hermine) in the Ruhr area in Germany and one (Finexcam) in Finland
were able to provide useful data sets. Mincam5 was blinded for a longer time
period by the full moon, RF1 suffered from clouds drifting through the field
of view, and at other sites skies cleared only later at night.
The four cameras recorded 93 Ursids and 42 sporadic meteors between December
22, 15:30 UT and December 23, 01 UT. From the first look it was obvious,
that Ursid rates were high right from the beginning of observation until
about 23 UT, and broke down dramatically thereafter. For the analysis, meteor
were summed up in 30 minute intervals and corrected for the radiant altitude.
In addition, an empirical correction factor was applied for those time
intervals where the full moon disturbed the field of view. In the end, the
data from the four cameras were averaged resulting in an activity profile,
that shows enhanced activity between 17 and 23 UT.
But was that indeed the expected outburst? Fortunately, there was already
special interest in the Ursids before, so I had done an analysis of the
shower with the same method in the previous year based on five data sets.
That could now be used for comparison. It became clear, that the activity
profile in 2007 was quite similar to the one of 2006, and rates were only
slightly higher. Since the profile of sporadic meteors looked the same as
well it can be ruled out, that this is only due to different observing
conditions (limiting magnitude, field of view). If there was indeed an
outburst, it must have consisted mainly of faint meteors - too faint to
be recorded by non-intensified cameras in a moonlit night.
It remains to mention, that the highest Ursid activity was observed in both
years in the evening of December 22, i.e. at a different solar longitude.
Let's now come to the annual statistics for 2007. In the last year,
22 observers (2006: 19) from 9 countries (2006: 6) have participated in
the IMO Video Meteor Network with 30 (2006: 28) distinct camera systems.
With respect to the number of observers, Germany (7) and Italy (5) are
on top, followed by Slovenia (3). All observers but Bob Lunsford (USA) are
based in Europe.
The slightly increased interest in the camera network reflects also in the
observation result. Even though we "only" got 364 observing nights this
time (Mai 28/29 was the only night with no observation in the last two years),
the overall effective observing time increased from nearly 15,000 hours
in 2006 to nearly 17,000 hours in 2007, and also the meteor number increased
from 70,000 to 75,000. Averaging over all cameras and nights, we
recorded 4.4 meteors per hour - slightly less than in the year before
(2006: 4.7).
Once more, August, October and December were particularly successful months.
Whereas most observing time was collected in October, we could record for
the first time more than 15,000 meteors a month in August. April is also
worthwhile to be mentioned, since this typically very poor month yielded
perfect observing conditions in 2007, in contrast to the two following months.
Month # Observing Effective Obs. # Meteors Meteors /
Nights Time [h] Hour
============================================================
January 31 1071.8 3188 3.0
February 28 1011.2 2720 2.7
March 31 1605.6 3466 2.2
April 30 2087.1 4823 2.3
May 30 880.9 2145 2.4
June 30 631.8 1864 3.0
July 31 1259.9 5912 4.7
August 31 1603.9 15185 9.5
September 30 1623.9 7609 4.7
October 31 1881.2 11535 6.1
November 30 1586.1 6807 4.3
December 31 1689.0 9816 6.0
============================================================
Overall 364 16932.4 75070 4.4
Looking at the complete video meteor database, we now collected between
10,000 (May) and 53,800 (October) meteors per month. The data set has
almost doubled since the last extensive meteor shower analysis in 2006,
which is why I intend to repeat the analysis this year.
In the last year, six (2006: 5) observers managed to take the magic hurdle
of 200 observing nights. In fact, what seemed to be almost impossible
before - I myself collected even well above 300 nights improving the record
from last years by 36 nights. Javor Kac, Flavio Castellani, Bernd
Brinkmann, Mihaela Triglav and Joerg Strunk follow in the statistics.
It should be mentioned, that Sirko Molau, Javor Kac and Joerg Strunk
usually operate three cameras in parallel.
The results for all observers are summarized in the next table.
Observer Country # Observing Effective Obs. # Meteors Meteors /
Nights Time [h] Hour
============================================================================
Sirko Molau Germany 324 3288.9 18326 5.6
Javor Kac Slovenia 256 2331.8 10253 4.4
Flavio Castellani Italy 238 1317.2 3253 2.5
Bernd Brinkmann Germany 220 833.3 3098 3.7
Mihaela Triglav Slovenia 208 1022.3 3544 3.5
Joerg Strunk Germany 201 1430.9 4692 3.3
Biondani Roberto Italy 153 872.0 2822 3.2
Enrico Stomeo Italy 145 1004.8 4214 4.2
Ilkka Yrjola Finland 142 770.3 3753 4.9
Wolfgang Hinz Germany 133 748.5 3713 5.0
Stane Slavec Slovenia 133 655.4 1601 2.4
Stephen Evans U.K. 108 710.3 3043 4.3
Orlando Benitez-S. Spain 86 280.0 787 2.8
Robert Lunsford U.S.A. 82 532.9 4867 9.1
Detlef Koschny Netherlands 70 516.5 1874 3.6
Maurizio Eltri Italy 45 373.3 1887 5.1
Stefano Crivello Italy 16 110.1 767 7.0
Rosta Stork Czech Rep. 8 70.0 2191 31.3
Niko Wuensche Germany 7 37.5 254 6.8
Milos Weber Czech Rep. 4 3.9 55 14.1
Ulrich Sperberg Germany 2 19.4 46 2.4
Daniel Fischer Germany 1 3.1 30 9.7
============================================================================
Overall 364 16932.4 75070 4.4
It remains to explain, how a single observer can collect 324 observing
nights in central Europe. The answer has two aspects:
On the hand hand, my cameras are installed at two observing sites at a
distance of about 500 kilometers. If it is clouded at one site, there are
still chances for a cloud gap at the second.
On the other hand, both observing sites seem to be well suited for central
European circumstances. Both camera systems are operated fully autonomously
and run stable such that they do not miss the slightest cloud gap. The
following statistics of the ten most successful cameras shows REMO1 in
Ketzuer in first and MINCAM1 in Seysdorf in second place.
Camera Site Observer # Obs. Eff. Obs. # Met. Met. /
Nights Time [h] Hour
===============================================================================
REMO1 Ketzuer (D) Sirko Molau 271 1243.5 4363 3.5
MINCAM1 Seysdorf (D) Sirko Molau 251 1247.8 4171 3.3
BMH1 Monte Baldo (I) Flavio Castellani 238 1317.2 3253 2.5
HERMINE Herne (D) Bernd Brinkmann 220 833.3 3098 3.7
METKA Konstanjevec (SL) Javor Kac 209 1168.6 3906 3.3
SRAKA Velenje (SL) Mihaela Triglav 208 1022.3 3544 3.5
MINCAM2 Herford (D) Joerg Strunk 184 565.2 1460 2.6
AVIS2 Seysdorf (D) Sirko Molau 155 797.6 9792 12.3
FIAMENE Verona (I) Biondani Roberto 153 872.0 2822 3.2
MIN38 Scorze (I) Enrico Stomeo 145 1004.8 4214 4.2
===============================================================================
All observation from 2007 are checked for consistency and inserted into the
video meteor database. They will be made available in PosDat format for
download at www.imonet.org soon.
Finally, I'd like to thank all observers in the camera network for the
good co-operation in the previous year, and to wish all of us a happy and
successful new observing year.
1. Observers
============
Code Name Place Camera FOV LM Nights Time Meteors
--------------------------------------------------------------------------------
BENOR Benitez-S. Las Palmas TIMES4 (1.4/50) 20 dg 3 mag 12 39.2 h 167
TIMES5 (0.95/50) 10 dg 3 mag 10 28.9 h 86
BRIBE Brinkmann Herne HERMINE (0.8/6) 55 dg 3 mag 20 88.8 h 372
CASFL Castellani Monte Baldo BMH1 (0.8/6) 55 dg 3 mag 23 207.0 h 538
CRIST Crivello Valbrevenna STG38 (0.8/3.8) 80 dg 3 mag 2 11.5 h 54
ELTMA Eltri Venezia MET38 (0.8/3.8) 80 dg 3 mag 3 18.9 h 203
EVAST Evans Moreton RF1 (0.8/12) 25 dg 5 mag 9 75.7 h 623
HINWO Hinz Brannenburg AKM2 (0.85/25) 32 dg 6 mag 16 124.8 h 591
KACJA Kac Kostanjevec METKA (0.8/8) 42 dg 4 mag 8 57.8 h 386
Kamnik REZIKA (0.8/6) 55 dg 3 mag 4 11.7 h 85
Ljubljana ORION1 (0.8/8) 42 dg 4 mag 10 42.5 h 313
KOSDE Koschny Noordwijkerh. ICC4 (0.85/25) 25 dg 5 mag 3 6.0 h 7
LUNRO Lunsford Chula Vista BOCAM (1.4/50) 60 dg 6 mag 17 136.7 h 2128
MOLSI Molau Seysdorf AVIS2 (1.4/50) 60 dg 6 mag 11 65.4 h 908
MINCAM1 (0.8/6) 55 dg 3 mag 17 75.2 h 386
Ketzuer REMO1 (0.8/3.8) 80 dg 3 mag 16 92.9 h 319
ROBBI Roberto Verona FIAMENE (0.8/3.8) 80 dg 3 mag 24 180.3 h 740
SLAST Slavec Ljubljana KAYAK1 (1.8/28) 50 dg 4 mag 6 36.2 h 143
STOEN Stomeo Scorze MIN38 (0.8/3.8) 80 dg 3 mag 16 141.1 h 646
STORO Stork Ondrejov OND1 (1.4/50) 55 dg 6 mag 1 2.7 h 67
STRJO Strunk Herford MINCAM2 (0.8/6) 55 dg 3 mag 2 42.6 h 110
MINCAM3 (0.8/8) 42 dg 4 mag 6 34.5 h 96
MINCAM5 (0.8/6) 55 dg 3 mag 6 45.4 h 178
TRIMI Triglav Velenje SRAKA (0.8/6) 55 dg 3 mag 12 50.6 h 237
WUNNI Wuensche Berlin ARMEFA (0.8/6) 55 dg 3 mag 5 29.5 h 78
YRJIL Yrjola Kuusankoski FINEXCAM (0.8/6) 55 dg 3 mag 7 46.4 h 422
--------------------------------------------------------------------------------
Sum 31 1689.0 h 9816
2. Observing Times (h)
======================
Dec 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
--------------------------------------------------------------------------------
BENOR - 1.8 - 0.2 - - - - - - - - 7.5 9.3 2.3
- 0.2 - - - - - - - - - - 3.8 9.4 2.2
BRIBE 2.5 0.9 5.2 - 0.3 - 0.3 - - - - 1.5 4.8 2.5 11.3
CASFL - - 7.0 9.0 8.5 3.5 - 5.0 12.0 8.0 11.0 4.9 13.0 6.0 3.0
CRIST - - - - - - - - - - - - 2.3 - -
ELTMA - - - - - - - - - - - - 9.3 1.8 -
EVAST - 7.1 - - - - 5.9 - - 10.7 11.4 11.7 6.5 - -
HINWO - - 7.0 - 8.0 - - 4.7 6.8 0.7 - - - - 4.4
KACJA 9.0 - - 6.6 8.6 6.6 - - - 4.7 - - 7.6 - -
- - - 1.1 7.5 - - - - - - - - - -
- - 1.4 4.9 2.0 - - - - - - 2.1 8.8 3.8 -
KOSDE - - - - - - - - - - - - - - -
LUNRO - - 11.2 11.9 11.9 1.7 - - - - - 9.2 2.4 7.7 6.0
MOLSI - - 0.3 - 1.3 - - 4.8 5.7 - - - 10.0 2.8 -
2.8 - 2.5 - 6.1 - - 2.7 5.3 0.2 - 0.9 8.2 2.1 -
10.8 3.3 2.8 3.9 5.9 - 6.5 5.5 3.5 - 1.0 - - 6.6 8.0
ROBBI - - 8.7 10.0 6.2 1.2 - 4.7 8.2 - 8.8 7.8 10.3 6.3 0.8
SLAST - - - 8.5 5.7 - - - - - - - 7.7 - -
STOEN - - - - 9.6 2.4 - 0.6 - - - 5.3 6.0 6.1 -
STRJO 0.7 - 0.5 - - - 1.8 - 0.5 - - - - - 4.7
- - - - - - - - - - - - - - 9.5
- - - - - - - - - - - - - - 7.7
TRIMI 6.5 - 6.6 6.1 7.8 0.7 - 0.3 - 8.2 1.0 0.7 5.7 - -
WUNNI - - - - - - - - - - - - - - -
YRJIL - - - - - - - - - - - 12.4 14.3 - -
----------------------------------------------------------------------------------
Sum 32.3 13.3 53.2 62.2 89.4 16.1 14.5 28.3 42.0 32.5 33.2 56.5128.2 64.4 59.9
Dec 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
------------------------------------------------------------------------------------
BENOR 2.5 1.8 - 3.9 4.3 3.1 2.0 - 0.5 - - - - - - -
3.8 0.5 - 2.8 4.4 1.7 - - 0.1 - - - - - - -
BRIBE 8.3 10.9 10.4 0.8 - 9.8 11.0 0.3 1.8 2.2 - - - 2.5 1.5 -
CASFL 11.0 13.0 10.0 12.9 10.9 12.9 - - - - - 7.3 9.9 8.1 12.8 7.3
CRIST - - - - - 9.2 - - - - - - - - - -
ELTMA - - - - 7.8 - - - - - - - - - - -
EVAST 5.3 - - - - - 11.3 - - - - - - 5.8 - -
HINWO - 10.0 13.1 13.1 13.1 - 6.6 - - 4.7 4.4 13.0 8.5 6.7 - -
KACJA - - 10.7 - - - - - - - - - - - - 4.0
- - - - - 1.8 - - - - 1.3 - - - - -
- 0.7 10.1 7.1 - - - - - - - - - - - 1.6
KOSDE - - - - - - 0.2 - 1.1 - - - - 4.7 - -
LUNRO 5.1 7.0 10.5 - - - - - 12.1 10.9 7.8 5.1 - - 5.9 10.3
MOLSI - 11.9 10.8 11.7 - - - - - - - - - 1.1 - 5.0
- 12.7 13.8 11.2 0.2 - - - - - - - 0.5 1.7 0.6 3.7
- - - - - - 2.9 - - 8.9 - - 14.1 6.5 2.0 -
ROBBI 7.8 8.2 10.8 10.8 6.8 9.4 - - 7.2 6.9 4.9 6.9 10.6 7.9 - 9.1
SLAST - - 7.1 4.7 - - - - - - - - - - - 2.5
STOEN 6.4 9.6 12.6 11.6 12.6 13.5 - - - - - 13.5 13.3 10.9 7.1 -
STRJO - - 5.0 - - 8.7 11.2 - 0.5 - - - 6.7 1.0 1.3 -
- 0.7 4.8 - - - 10.9 - - - - - 7.4 1.2 - -
- - 4.3 - - 11.0 10.1 - - - - - 11.9 0.5 - -
TRIMI - - 6.2 - - - - - - - - - - - - 0.8
WUNNI - - - - - - - - - 6.7 0.5 - 14.1 8.0 - 0.2
YRJIL - - 1.9 4.7 0.9 - 9.8 - - - - - - - 2.4 -
--------------------------------------------------------------------------------------
Sum 50.2 87.0141.2 95.3 61.0 81.1 76.0 0.3 23.3 40.3 17.6 45.8 97.0 66.6 33.6 44.5
3. Results (Meteors)
====================
Dec 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
--------------------------------------------------------------------------------
BENOR - 3 - 1 - - - - - - - - 49 59 7
- 2 - - - - - - - - - - 14 26 9
BRIBE 9 3 19 - 1 - 1 - - - - 6 22 26 55
CASFL - - 16 15 14 4 - 6 23 26 32 17 127 40 4
CRIST - - - - - - - - - - - - 30 - -
ELTMA - - - - - - - - - - - - 160 14 -
EVAST - 56 - - - - 25 - - 76 116 154 106 - -
HINWO - - 24 - 27 - - 6 78 1 - - - - 42
KACJA 37 - - 35 50 26 - - - 12 - - 163 - -
- - - 3 74 - - - - - - - - - -
- - 2 13 4 - - - - - - 19 154 57 -
KOSDE - - - - - - - - - - - - - - -
LUNRO - - 122 122 105 6 - - - - - 140 158 709 318
MOLSI - - 4 - 8 - - 29 130 - - - 298 74 -
15 - 5 - 19 - - 3 41 1 - 9 117 33 -
36 11 4 5 19 - 22 20 12 - 1 - - 76 16
ROBBI - - 23 19 14 2 - 14 36 - 40 66 147 53 2
SLAST - - - 18 10 - - - - - - - 72 - -
STOEN - - - - 29 2 - 3 - - - 76 49 51 -
STRJO 2 - 2 - - - 5 - 2 - - - - - 10
- - - - - - - - - - - - - - 24
- - - - - - - - - - - - - - 46
TRIMI 20 - 27 21 35 4 - 2 - 39 4 3 56 - -
WUNNI - - - - - - - - - - - - - - -
YRJIL - - - - - - - - - - - 123 216 - -
--------------------------------------------------------------------------------
Sum 119 75 248 252 409 44 53 83 322 155 193 613 1938 1218 533
Dec 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
-------------------------------------------------------------------------------------
BENOR 8 5 - 10 11 7 5 - 2 - - - - - - -
13 2 - 4 8 7 - - 1 - - - - - - -
BRIBE 43 43 30 1 - 41 43 2 7 6 - - - 8 6 -
CASFL 19 31 19 34 21 23 - - - - - 12 12 9 23 11
CRIST - - - - - 24 - - - - - - - - - -
ELTMA - - - - 29 - - - - - - - - - - -
EVAST 17 - - - - - 54 - - - - - - 19 - -
HINWO - 76 76 56 56 - 39 - - 17 20 27 36 10 - -
KACJA - - 51 - - - - - - - - - - - - 12
- - - - - 7 - - - - 1 - - - - -
- 3 41 18 - - - - - - - - - - - 2
KOSDE - - - - - - 2 - 1 - - - - 4 - -
LUNRO 46 60 56 - - - - - 56 43 55 42 - - 30 60
MOLSI - 129 141 56 - - - - - - - - - 3 - 36
- 40 58 29 1 - - - - - - - 2 2 2 9
- - - - - - 14 - - 27 - - 37 14 5 -
ROBBI 26 24 35 38 19 25 - - 19 16 21 25 32 14 - 30
SLAST - - 31 10 - - - - - - - - - - - 2
STOEN 32 62 57 49 46 55 - - - - - 46 36 20 33 -
STRJO - - 10 - - 21 39 - 2 - - - 11 2 4 -
- 2 12 - - - 42 - - - - - 14 2 - -
- - 14 - - 52 36 - - - - - 29 1 - -
TRIMI - - 23 - - - - - - - - - - - - 3
WUNNI - - - - - - - - - 9 1 - 46 21 - 1
YRJIL - - 3 18 1 - 51 - - - - - - - 10 -
-------------------------------------------------------------------------------------
Sum 204 477 657 323 192 262 325 2 88 118 97 152 255 129 113 166
Sirko Molau, 2008/01/17