Results of the IMO Video Meteor Network - April 2005
====================================================
April started with four clear nights, which could be used by almost every
observer in the video network. After that, the weather deterriorated strongly
and cleared only sporadically. However, just in time for the Lyrids the
clouds disappeared, such that on April 21 and 22 almost every observer resumed
the obsevation. Thereafter it got rainy and cold, but thanks to the six nights
with globally clear skies we could collect more observing hours this April
than in the years before.
On April 6, we had the third anniversary of the "Neuschwanstein" meteorite
fall. Since its orbit was very similar to the orbit of "Pribram" which
fell on April 6, 1959, it was suspected that there might exist an meteorite
stream. Given the radiant of alpha = 192 deg, delta = +19 deg and v_inf = 17km/s
I checked the video data for possible meteor activity from the "Pribramids",
but I was not successful. Out of 693 meteors recorded between April 1 and 15,
622 were classified as sporadic, 54 as Virginids and only 17 as "Pribramids".
In the individual nights, the "Pribramid" rate was 1/20 of the sporadic rate
or below, and those 17 were probably only by chance alignments of sporadic
meteors.
The Lyrid maximum was expected to occur in the late morning of April 22.
I corrected the video data of all cameras (93 Lyrids overall) for the radiant
altitude at the observing sites, binned them in 30 min intervals, and
accumulated the data for all cameras. The resulting profile shows a peak
between 0:30 and 2:30 UT - after that the rate seems to decline again. It must
be noted, though, that the interference by the moon reduced towards the
morning hours, whereas twilight interfered remarkably in the last interval.
These factors could not be considered in the analysis, which is why the peak
needs an independent confirmation from visual observations.
I've been searching for a long time for the reason why there is a big
performance gap between individual Mintron cameras. The theory I presented last
month seems to be proven now. For best performance, the contrast of the frame
grabber needs to be maximized and the brightness must be adjusted such that
the background is dark gray. The image becomes very noisy this way, but the
limiting magnitude increases by about one magnitude. On April 9 I modified
the settings of MINCAM1 accordingly. Whereas in January (1.4 vs. 2.7 meteors / h),
February (1.4 vs. 1.8 meteors / h) and March (1.2 vs. 1.6 meteors / h)
this camera was clearly inferiour to MINCAM2, both cameras performed
equally well in the second half of April: 2.1 vs. 2.0 meteors / h! Especially
at the Lyrid maximum, MINCAM1 showed excellence performance and recorded almost
as many meteors as the best image intensified camera AVIS2 at those moonlit
skies.
1. Observers
============
Code Name Place Camera FOV LM Nights Time Meteors
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BENOR Benitez-S. Las Palmas TIMES5 (0.8/6) 50 dg 3 mag 6 54.6 h 12
EVAST Evans Moreton RF1 (1.2/12) 20 dg 4 mag 7 50.4 h 89
KACJA Kac Kostanjevec METKA (0.8/8) 42 dg 2 mag 14 109.6 h 124
KOSDE Koschny Noordwijkerh. ICC3 (0.85/25) 25 dg 6 mag 9 52.3 h 137
MOLSI Molau Seysdorf AVIS2 (1.4/50) 60 dg 6 mag 10 55.8 h 477
MINCAM1 (0.8/6) 50 dg 3 mag 18 91.2 h 153
SLAST Slavec Ljubljana KAYAK1 (1.8/28) 50 dg 4 mag 11 61.3 h 107
STORO Stork Ondrejov OND1 (2.4/35) 30 dg 7 mag 3 19.8 h 38
Kunzak KUN1 (2.4/35) 30 dg 7 mag 5 37.3 h 64
KUN2 (2.8/16) 80 dg 5 mag 1 8.6 h 6
STRJO Strunk Leopoldshoehe MINCAM2 (0.8/6) 55 dg 3 mag 24 76.4 h 155
MINCAM3 (0.8/8) 42 dg 4 mag 15 72.2 h 141
YRJIL Yrjola Kuusankoski FINEXCAM (0.8/6) 50 dg 3 mag 21 108.0 h 164
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Sum 29 797.5 h 1667
2. Observing Times (h)
======================
Apr 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
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BENOR 10.5 - - - - - 10.5 - - 7.6 - - - - -
EVAST - 7.9 - 7.8 - - - 7.3 - - 7.4 - - - -
KACJA 8.9 8.8 8.8 7.8 9.1 7.9 - - - - - - - 6.1 8.1
KOSDE 7.6 4.3 - - - - - - - - 6.2 - - - -
MOLSI 8.9 - 8.6 6.5 - 0.5 - - - - - - - 2.6 5.0
9.2 9.5 9.5 9.4 - 1.3 - - 2.1 - - - 2.3 4.7 5.7
SLAST 5.7 5.0 8.3 7.9 6.1 6.6 - - - - - - - 4.0 2.0
STORO - - 8.6 8.7 - 2.5 - - - - - - - - -
8.3 8.7 8.6 8.6 - 3.1 - - - - - - - - -
- - - 8.6 - - - - - - - - - - -
STRJO 6.1 8.6 8.5 1.0 2.5 0.6 1.5 1.2 - 2.6 5.1 - 2.7 1.5 0.7
7.9 8.6 8.5 2.0 3.2 - 3.2 - - - 4.9 - - - -
YRJIL 6.7 7.3 7.2 5.3 6.2 6.7 - 6.2 - 5.1 3.2 - 6.1 - 2.2
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Sum 79.8 68.7 76.6 73.6 27.1 29.2 15.2 14.7 2.1 15.3 26.8 - 11.1 18.9 23.7
Apr 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
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BENOR - - - - - - 10.5 - - - - - 8.6 6.9 -
EVAST 7.3 - 6.5 - - 6.2 - - - - - - - - -
KACJA - 8.2 - - - 6.1 7.1 7.7 - - - - 7.4 - 7.6
KOSDE - - - - 5.2 7.7 3.5 6.5 5.5 5.8 - - - - -
MOLSI - - - - - 6.0 7.1 - - - 4.1 - - - 6.5
2.2 - - - 0.9 8.2 8.3 2.2 - - 2.4 3.6 - 1.9 7.8
SLAST - 2.0 - - - 6.7 7.0 - - - - - - - -
STORO - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - -
- - - - - - - - - - - - - - -
STRJO 1.2 1.8 - - 7.2 7.1 7.0 1.4 0.5 - - 4.4 1.0 1.0 1.2
2.0 - - - 7.2 7.0 4.0 1.5 - - - 6.2 - 2.5 3.5
YRJIL 5.6 5.0 - 3.8 - 4.4 4.6 4.9 4.6 4.6 4.5 - 3.8 - -
--------------------------------------------------------------------------------
Sum 18.3 17.0 6.5 3.8 20.5 59.4 59.1 24.2 10.6 10.4 11.0 14.2 20.8 12.3 26.6
3. Results (Meteors)
====================
Apr 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
--------------------------------------------------------------------------------
BENOR 1 - - - - - 1 - - 2 - - - - -
EVAST - 11 - 6 - - - 16 - - 11 - - - -
KACJA 6 10 7 9 6 11 - - - - - - - 5 10
KOSDE 21 9 - - - - - - - - 11 - - - -
MOLSI 107 - 82 59 - 2 - - - - - - - 9 40
9 16 8 3 - 1 - - 4 - - - 4 3 7
SLAST 7 9 16 9 14 12 - - - - - - - 2 1
STORO - - 24 13 - 1 - - - - - - - - -
15 15 21 11 - 2 - - - - - - - - -
- - - 6 - - - - - - - - - - -
STRJO 10 16 12 2 6 1 4 2 - 5 11 - 4 3 3
17 13 15 2 4 - 9 - - - 7 - - - -
YRJIL 15 5 9 5 3 8 - 3 - 11 7 - 7 - 5
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Sum 208 104 194 125 33 38 14 21 4 18 47 - 15 22 66
Apr 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
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BENOR - - - - - - 1 - - - - - 6 1 -
EVAST 15 - 8 - - 22 - - - - - - - - -
KACJA - 9 - - - 8 19 7 - - - - 7 - 10
KOSDE - - - - 21 45 5 7 9 9 - - - - -
MOLSI - - - - - 52 40 - - - 30 - - - 56
4 - - - 2 42 29 3 - - 2 9 - 2 5
SLAST - 2 - - - 21 14 - - - - - - - -
STORO - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - -
- - - - - - - - - - - - - - -
STRJO 2 4 - - 20 14 15 4 1 - - 9 2 2 3
4 - - - 17 20 9 6 - - - 8 - 3 7
YRJIL 10 10 - 5 - 16 15 8 7 4 6 - 5 - -
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Sum 35 25 8 5 60 240 147 35 17 13 38 26 20 8 81
Sirko Molau, 2005/05/16