(meteorobs) 2006 Geminids from Edmonton: Part One (?)
Bruce McCurdy
bmccurdy at telusplanet.net
Thu Dec 14 02:59:31 CET 2006
While we're still hoping to chase sucker holes in pursuit of the Geminid
peak tonight, last night there were no such concerns as conditions here in
north-central Alberta were very good. Alister Ling and I headed out to RASC
Edmonton Centre's primary observing site at the Beaver Hills Dark Sky
Preserve, and got a solid four hours of observing in under gradually
deteriorating skies, with the Moon eventually following the radiant up the
sky. Limiting magnitude was pretty good, although the Milky Way was not
that well defined; in fact in one moment of silliness I called the sky "way
milky". Rates were fairly consistent throughout at about one meteor every
two minutes, in fact my final count for the night was exactly 120 meteors in
240 minutes, including 85 Geminids. I observed a higher percentage of bright
meteors after the first 90 or so minutes.
It would have been worth the trip to see just one of those, a fabulous
emerald green shadowcaster majestically dropping towards the western horizon
just before 3 a.m. Luckily we both saw it, and after some discussion in
which we both referred to our experience observing Iridium flares, we agreed
on a magnitude estimate of -7. The principal colour was superb, a very pure
flash that I referred to as emerald while Alister compared it to a glacial
lake, and it had a pinkish fringe/afterglow which may have been a contrast
effect. (?)
In general the meteors displayed very brief if any wakes, with virtually
no persistent trains. As is our usual practice, we monitored forward
scattering by car radio, with more frequent activity on the radio than
visually. Simultaneous radio bursts confirmed about 20% of my visual
meteors. Once again we noticed that airplanes caused long radio reflections;
I called them "plane trains". One of the longest bursts rather ironically
featured the Ozzy Osborne classic "Crazy Train".
My new method of recording every meteor is labour-intensive, especially
when it comes to transcribing the tapes. I still have my second night of
Orionid observing and two nights near the Leonid peak to report, but thought
I would start to catch up with what is current. Using the
sincerest-form-of-flattery principle, I have imitated the method of the
accomplished meteor observer Paul Martsching of Iowa in recording the
following "play-by-play" account of last night's observations. Paul's method
has the virtue of brevity which does *not* come easy to me!
Bruce
*****
***
Date: 2006 December 13 06:37-10:45 UT (MST 2006 December 12-13. 23:37 -
03:45) Teff 4.00 hours
Observer: Bruce McCurdy
Site: Beaver Hills Dark Sky Preserve (Blackfoot Staging Area), 50 km east of
Edmonton, Alberta
(53°32'12" N, 112° 46m 48s W, elevation 711 metres)
Primary method: Visual; microcassette recorder and talking watch;
Secondary method: Audio; monitoring by car FM radio for forward scattering
(FM 92.1)
***
06:37-07:37; 0° C.; clear; average limiting magnitude 6.2; facing SSE 45°;
Teff 1.0 hour
Time type mag. comment
--------------------------------
06:37 GEM +4 Looking SSE
06:37 GEM +4
06:44 GEM +3
06:46 MON +3
06:50 GEM +3
06:52 GEM +4
06:54 Spor +1 Simultaneous Radio Burst (SRB)
06:55 GEM +4
06:55 MON +4
06:56 Spor +3 SRB
06:57 GEM +4
07:02 GEM 0 SRB
07:02 GEM +4
07:04 GEM +4
07:04 GEM +3
07:09 GEM +2
07:10 Spor +3
07:13 Spor +1 Erratic
07:19 GEM +2
07:23 MON 0
07:23 GEM +2
07:27 ANT +1 brief wake
07:30 GEM +3
07:31 GEM +4
07:31 GEM +3
07:31 GEM +2
07:35 GEM +1 brief wake
07:35 GEM +1
Antihelion 1: +1
Monocerotid 3: 0, +3, +4
Geminid 20: 0, +1 (2), +2 (4), +3 (5), +4 (8)
Hydrid: none
Sporadic 4: +1 (2), +3 (2)
Total meteors: twenty-eight
***
07:37-08:37; -2° C.; clear; average limiting magnitude 6.1; facing SSE 45°;
Teff 1.0 hour
Time type mag. comment
--------------------------------
07:39 GEM +4
07:43 GEM +3
07:43 GEM +3
07:46 MON +2
07:47 HYD +1
07:47 GEM +4
07:53 HYD +4
07:53 GEM +4
07:58 GEM +2
07:59 GEM +1 SRB
08:10 GEM +1
08:12 GEM -1 close to radiant, wake
08:12 GEM +4
08:12 Spor +4
08:14 GEM +1
08:18 GEM -1
08:18 GEM +4
08:21 Spor 0 SRB
08:23 Spor +4 Moon risen
08:25 MON +2
08:26 GEM -3 majestic, white, wake
08:26 GEM +3
08:29 Spor 0 wake
08:32 GEM -2 persistent train
08:32 Spor +3
08:35 Spor +2
Antihelion: none
Monocerotid 2: +2 (2)
Geminid 16: -3, -2, -1 (2), +1 (3), +2, +3 (3), +4 (5)
Hydrid 2: +1, +4
Sporadic 6: 0 (2), +2, +3, +4 (2)
Total meteors: twenty-six
***
08:37-09:45; -4° C.; clear; average limiting magnitude 5.9; facing SSE 45°,
then NNW 45°; Teff 1.0 hour
Time type mag. comment
--------------------------------
08:37 HYD +3
08:39 Spor 0
08:39 GEM +3
08:45 GEM +5
08:46 GEM +3
08:48 GEM +4
08:48 GEM +3 SRB
08:49 MON +3
[8 minute break 8:52-9:00]
09:03 Spor +2 Looking NNW
09:05 GEM +3
09:09 GEM +4
09:10 GEM +2 SRB
09:11 GEM +2 SRB
09:12 GEM +2
09:15 GEM 0
09:15 GEM -1
09:17 GEM +3
09:22 GEM +2 SRB
09:23 GEM +1 SRB; erratic
09:23 GEM +1 SRB
09:25 Spor +4
09:26 GEM +1 wake
09:27 Spor +3
09:27 Spor +3 2 in 1.5 sec, very similar
09:28 Spor +2
09:28 GEM -1 persistent train
09:29 GEM +2
09:29 GEM +1
09:31 GEM +4 SRB
09:36 GEM -2 wake; blue-white
09:39 GEM +3 wake
09:40 GEM +1 wake
Antihelion: none
Monocerotid 1: +3
Geminid 24: -2, -1 (2), 0, +1 (5), +2 (5), +3 (6), +4 (3), +5
Hydrid 1: +3
Sporadic 6: 0, +2 (2), +3 (2), +4
Total meteors: thirty-two
***
09:45-10:45; -6° C.; incoming cloud; average limiting magnitude 5.7; facing
NNW 45°; Teff 1.0 hour
Time type mag. comment
--------------------------------
09:46 Spor +4 SRB
09:47 GEM -7 Emerald green, pinkish fringe, slow flash point, ~2 sec,
wake but no train
09:48 GEM +3
09:48 GEM +4
09:50 HYD +2
09:51 GEM +4 SRB
09:51 Spor +5 SRB
09:53 GEM +4
09:54 Spor 0 coppery, erratic
10:01 GEM +1
10:02 Spor +2
10:02 GEM +2
10:05 Spor +3 very fast
10:08 GEM +2 SRB
10:12 GEM +2 SRB
10:15 GEM 0 wake, clouds incoming
10:19 GEM +3 SRB
10:21 GEM +1 SRB, wake
10:21 GEM +2 SRB
10:22 GEM +2
10:23 GEM +5
10:23 GEM +2 SRB
10:30 GEM +2
10:30 GEM +3
10:31 GEM +1
10:32 Spor +3
10:32 GEM +1 SRB
10:32 Spor +3
10:32 GEM +2 "Fat meteor"
10:34 GEM +2 wake
10:37 GEM +2
10:39 Spor 0 coppery
10:40 GEM +2 SRB
10:44 GEM +1 SRB
Antihelion: none
Monocerotid: none
Geminid 25: -7, 0, +1 (5), +2 (11), +3 (3), +4 (3), +5
Hydrid 1: +2
Sporadic 8: 0 (2), +2, +3 (3), +4, +5
Total meteors: thirty-four
***
Observing summary: Teff = 4.0 hours
Antihelion 1: +1
Monocerotid 6: 0, +2 (2), +3 (2), +4
Geminid 85: -7, -3, -2 (2), -1 (4), 0 (3), +1 (15), +2 (21), +3 (17), +4
(19), +5 (2)
Hydrid 4: +1, +2, +3, +4
Sporadic 24: 0 (5), +1 (2), +2 (4), +3 (8), +4 (4), +5
Total meteors: one hundred twenty
*****
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