Results of the IMO Video Meteor Network - September 2007
========================================================
September 2007 was an unexceptional month. The first half was fair to
middling, but a short glimpse on the statistics of the second half shows
"compact observing blocks". September 21 in 22 were in particular favorable.
In both nights we could collect more than a hundred hours of observing time.
An overall of five observers managed to obtain more than 20 observing nights,
and the monthly totals of 1500 hours and 7000 meteors were also considerable.
Highlight of the month was without doubt the Aurigid outburst near noon (UT)
of September 1, which could be observed from the American west coast.
Unfortunately, Bob Lunsford, our only regular observer in place, has currently
severe computer problems, which is why his video data are not yet analysed.
However, Bernd Brinkmann and Daniel Fischer operated one Mintron camera each
at Fremont Peak in California. Their fields of view slightly overlapped, since
the cameras were operated in a double-station scheme with cameras of
Apostolos Christou observing at Lick observatory. Right now, the observations
are analysed at Armagh Observatory. Here, a first look at the single
station results of the two AKM members is given.
First back to the predictions: The peak time was forecasted by Peter Jenniskens
and Jeremie Vaubaillon to 11:36 UT ± 20 min. The equivalent ZHR (i.e. the
short term ZHR at the time of maximum) was expected to reach about 200. Already
first reports confirmed the outburst, even though the eZHR was only close to
100. Every visual observers spotted between 30 and 40 on average quite bright
Aurigids. The preliminary analysis of visual data from four observers
prepared by Daniel Fischer (as always a highly scientific free-hand sketch on
scale paper ;-) yielded an early maximum at about 11:15 UT. The online activity
graph of IMO came to the same conclusion, that the maximum was about 20 min
early.
According to the IMO Working List of Meteor Showers, the AUR radiant was
expected at α=84°, δ=42°. Peter Jenniskens listed the position with α=92°, δ=39°.
Bob Lunsford reported, that he visually observed a double radiant. One
component matched with the IMO position, whereas the other was farther east
(α=95°, δ=42°). Pete Gural, who observed together with Bob, confirmed two
equally strong radiants with his Meteorscan software.
Now back to the observations of the two AKM observers: Bernds camera HERMINE
recorded 40 meteors between 10:08 and 13:08 UT, 11 of them being AUR. Daniels
camera FISHCAM was operated with four times integration (resulting in larger
angular velocity errors) between 10:00 and 13:06. It recorded 30 meteors, among
them 10 Aurigids. If the double detections are omitted, we end up with a data
set of 16 Aurigids recorded between 10:49 and 12:02 UT. Highest activity
occured in the interval 11:15-11:20. This fits well to the visual
results, whereat their dataset is much bigger, of course.
The MetRec radiant plots show, that the fields of view were
not optimal for radiant position determination from single station data.
However, it becomes obvious that the radiant position differed significantly
from the value given in the IMO Shower List, and that these video data show
only one radiant.
A more detailed analysis of the 16 Aurigids with the Radiant software
underlines the results. The radiant was located at α=91°, δ=39°, which matches
almost exactly the position given by Peter Jenniskens. There is no double
radiant structure.
Summary: THE big Aurigid outburst that some observers had hoped for in secret
did not show up, but the observations agreed with the predictions within the
given error bars. The outburst can be compared with the alpha Monocerotids in
1995, even though today's forecasting methods are naturally much more
elaborate.
1. Observers
============
Code Name Place Camera FOV LM Nights Time Meteors
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BRIBE Brinkmann Herne HERMINE (0.8/6) 55 dg 3 mag 11 57.1 h 220
FISHCAM (0.8/6) 55 dg 3 mag 1 3.1 h 30
CASFL Castellani Monte Baldo BMH1 (0.8/6) 55 dg 3 mag 24 136.5 h 377
CRIST Crivello Valbrevenna STG38 (0.8/3.8) 80 dg 3 mag 4 25.3 h 111
ELTMA Eltri Venezia MET38 (0.8/3.8) 80 dg 3 mag 8 71.1 h 222
EVAST Evans Moreton RF1 (0.8/12) 25 dg 5 mag 14 89.4 h 335
HINWO Hinz Brannenburg AKM2 (0.85/25) 32 dg 6 mag 3 22.8 h 154
KACJA Kac Kostanjevec METKA (0.8/8) 42 dg 4 mag 19 132.8 h 489
Kamnik REZIKA (0.8/6) 55 dg 3 mag 6 35.0 h 181
Ljubljana ORION1 (0.8/8) 42 dg 4 mag 23 116.7 h 628
MOLSI Molau Seysdorf AVIS2 (1.4/50) 60 dg 6 mag 15 99.3 h 1737
MINCAM1 (0.8/6) 55 dg 3 mag 22 114.7 h 474
ROBBI Roberto Verona FIAMENE (0.8/3.8) 80 dg 3 mag 16 111.4 h 287
SLAST Slavec Ljubljana KAYAK1 (1.8/28) 50 dg 4 mag 8 30.1 h 61
STOEN Stomeo Scorze MIN38 (0.8/3.8) 80 dg 3 mag 14 84.9 h 306
STRJO Strunk Herford MINCAM2 (0.8/6) 55 dg 3 mag 19 41.1 h 115
MINCAM3 (0.8/8) 42 dg 4 mag 4 17.5 h 42
MINCAM5 (0.8/6) 55 dg 3 mag 7 37.9 h 129
TRIMI Triglav Velenje SRAKA (0.8/6) 55 dg 3 mag 21 141.5 h 449
YRJIL Yrjola Kuusankoski FINEXCAM (0.8/6) 55 dg 3 mag 24 121.8 h 737
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Sum 30 1490.0 h 6984
2. Observing Times (h)
======================
Sep 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
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BRIBE 3.0 - - - - - - - - - - - - - 4.0
3.1 - - - - - - - - - - - - -
CASFL 1.0 3.0 - 4.8 1.5 8.0 3.0 7.0 5.0 5.0 6.5 8.4 7.3 4.0 3.1
CRIST 7.5 - - - - - - 6.4 - - - - - - 7.8
ELTMA - 7.0 - - - - - - - - 8.4 8.9 9.4 9.1 -
EVAST 4.2 - 7.9 2.3 7.7 - 5.7 - - 8.1 6.2 8.2 4.8 8.7 8.8
HINWO - - - - - - - - - - - - - - -
KACJA 8.3 - 1.9 - - - - 4.9 7.3 - 1.8 7.2 8.6 4.0 3.2
- - - 1.5 - - - - - - - - - - 0.7
6.4 0.1 - 1.0 - 0.3 2.5 8.1 7.0 - 8.0 5.2 7.3 4.2 4.6
MOLSI - - - - - - - - 5.1 - - 6.6 6.4 3.7 9.0
- - 1.4 1.0 - - - - 6.9 0.1 - 7.5 9.6 4.1 8.2
ROBBI - - - 9.0 - 8.1 3.2 6.2 3.7 - 9.4 - 7.5 3.6 4.4
SLAST - - - - - - - - - - - - - - 5.0
STOEN - 8.4 - 7.3 - - 1.7 9.0 - - 1.6 9.5 9.2 9.2 -
STRJO 0.5 - 0.5 2.3 - - 0.4 - - - 2.0 1.5 5.8 2.6 5.0
- - - - - - - - - - - - - - 6.0
- - - - - - 0.8 - - - - - - - 8.8
TRIMI 8.2 - - 6.3 - 0.8 - 8.0 6.3 - 3.8 8.7 9.0 4.3 3.2
YRJIL 2.5 - 5.7 6.9 - 7.1 6.4 7.4 6.5 6.4 6.3 7.4 1.2 2.1 4.5
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Sum 44.7 18.5 17.4 42.4 9.2 24.3 23.7 57.0 47.8 19.6 54.0 79.1 86.1 59.6 86.3
Sep 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
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BRIBE 5.5 - - 6.3 - 3.4 10.5 8.0 5.6 4.6 1.9 - - - 4.3
- - - - - - - - - - - - - - -
CASFL - - 6.1 9.7 8.7 9.9 9.8 9.1 4.9 - - - 1.0 1.3 8.4
CRIST - - - - - - 3.6 - - - - - - - -
ELTMA - - - - 9.2 9.0 - - - - - - - - 10.1
EVAST - 6.7 - - - - 4.4 - - - - - - 5.7 -
HINWO - - - - - - 6.1 9.6 - - - - - - 7.1
KACJA 9.1 6.9 - 6.6 8.0 10.1 9.3 8.5 6.5 - - - - 10.0 10.6
9.8 - - - - 7.4 9.7 - 5.9 - - - - - -
9.3 3.3 3.6 6.2 9.8 7.8 7.8 5.8 1.9 - - - 1.0 - 5.5
MOLSI 8.8 - - 5.2 8.6 9.3 9.4 9.0 3.8 - - 2.3 - 5.4 6.7
9.4 1.3 2.7 4.5 9.0 10.1 10.1 10.2 6.4 0.2 - 1.4 0.2 3.3 7.1
ROBBI - - 8.8 7.2 9.4 8.9 - 9.1 3.6 - - - - - 9.3
SLAST 8.4 2.1 - - - 6.1 - - 3.0 1.4 - - - 0.4 3.7
STOEN 2.0 0.3 - 3.2 9.7 9.7 - - - - - - - - 4.1
STRJO 3.4 - 3.7 0.5 - 1.5 4.9 2.0 - 1.5 0.5 0.5 - - 2.0
- - 5.8 - - 3.1 2.6 - - - - - - - -
4.9 - 7.2 0.8 - 7.3 8.1 - - - - - - - -
TRIMI 8.2 7.6 3.6 9.5 9.0 7.8 8.7 7.3 - - - - 3.7 8.8 8.7
YRJIL 6.4 6.9 - 8.4 1.9 1.1 6.6 3.0 7.1 2.1 - - - 2.6 5.3
--------------------------------------------------------------------------------
Sum 85.2 35.1 41.5 68.1 83.3112.5111.6 81.6 48.7 9.8 2.4 4.2 5.9 37.5 92.9
3. Results (Meteors)
====================
Sep 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
--------------------------------------------------------------------------------
BRIBE 40 - - - - - - - - - - - - - 30
30 - - - - - - - - - - - - - -
CASFL 1 5 - 14 3 12 4 18 10 14 10 20 13 10 3
CRIST 34 - - - - - - 25 - - - - - - 33
ELTMA - 28 - - - - - - - - 34 22 24 23 -
EVAST 16 - 33 7 24 - 29 - - 38 17 17 23 32 36
HINWO - - - - - - - - - - - - - - -
KACJA 35 - 6 - - - - 17 37 - 4 27 38 10 8
- - - 3 - - - - - - - - - - 2
40 1 - 6 - 2 7 59 53 - 52 47 48 23 10
MOLSI - - - - - - - - 140 - - 124 175 33 193
- - 3 6 - - - - 31 1 - 18 25 4 24
ROBBI - - - 28 - 18 8 19 10 - 29 - 17 7 7
SLAST - - - - - - - - - - - - - - 12
STOEN - 24 - 45 - - 6 39 - - 8 15 39 24 -
STRJO 1 - 1 6 - - 1 - - - 4 5 12 11 17
- - - - - - - - - - - - - - 14
- - - - - - 2 - - - - - - - 36
TRIMI 26 - - 17 - 3 - 21 25 - 21 18 23 12 4
YRJIL 26 - 6 70 - 64 69 49 26 70 48 58 3 3 22
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Sum 249 58 49 202 27 99 126 247 332 123 227 371 440 192 451
Sep 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
--------------------------------------------------------------------------------
BRIBE 19 - - 10 - 15 35 20 19 15 8 - - - 9
- - - - - - - - - - - - - - -
CASFL - - 20 17 24 17 14 18 9 - - - 1 2 18
CRIST - - - - - - 19 - - - - - - - -
ELTMA - - - - 35 24 - - - - - - - - 32
EVAST - 40 - - - - 9 - - - - - - 14 -
HINWO - - - - - - 59 66 - - - - - - 29
KACJA 30 34 - 30 31 27 32 24 22 - - - - 26 51
31 - - - - 45 66 - 34 - - - - - -
43 8 23 48 55 33 23 17 8 - - - 3 - 19
MOLSI 195 - - 71 157 168 166 169 21 - - 5 - 43 77
51 5 17 15 48 39 51 58 12 1 - 3 1 29 32
ROBBI - - 23 13 22 20 - 29 12 - - - - - 25
SLAST 20 6 - - - 9 - - 3 1 - - - 1 9
STOEN 4 1 - 3 47 40 - - - - - - - - 11
STRJO 6 - 10 1 - 4 16 6 - 3 1 1 - - 9
- - 15 - - 5 8 - - - - - - - -
15 - 33 2 - 20 21 - - - - - - - -
TRIMI 24 22 9 40 37 19 26 18 - - - - 14 39 31
YRJIL 38 25 - 69 3 1 22 2 40 6 - - - 5 12
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Sum 476 141 150 319 459 486 567 427 180 26 9 9 19 159 364
Sirko Molau, 2007/10/23