From: "Kim Youmans" <ksyo@b...>
Date: Sun Dec 12, 2004 1:06 am
Subject: (meteorobs) Geminds Dec 11, 2004 East GA
This morning I completed the first watch of what will hopefully be a
three-, if not four-, night Geminid
"campaign." I was treated to a very clear sky upon arrival at my site at
1:00 AM local time. The drawback was, like Bob, I too faced a fairly stiff
wind that came and went throughout the session. The pine forest was quiet
on this late fall morning save for my occasional "whoop" as yet another
negative magnitude would appear -- during the first period there were four
of these. One GEM on the eastern horizon between the scrub oaks, blazed up
to -5 if not brighter at 06:22 UT. At 06:41 a wake-less, trainless, -3 GEM
dropped down through western Orion like a shiny green holiday ornament. The
first hour was very busy, 18 GEM's and 12 others. It was also considerably
brighter than the second hour, with 14 GEM's and 10 others, for a total of
54 meteors in just under two hrs teff.
****************************************************************
OBSERVER: Kim S. Youmans (YOUKI) DATE: 12-10/11-2004
BEGIN:06:00 UT END 8:00 UT LOCATION: Treutlen Co, Ga.
82. 24' 25" W; 32. 24' 45" N
METHOD: Tape Elev. 240 ft
Facing South, sky 0 %0bscured
No Breaks; Mean Sol long=259.520 DEC 11 2004
Mean LM +6.46
FOV Mid-session 7 hr +13; Total Teff=1.97
SPO(8) GEM(32) ANT(6) MON(4) HYD(4) Total (54)
Period 1
06:00-7:00UT SPO(4) GEM(18) ANT/XOR(3)
MON(2) HYD(3) Total (30)
Dead time = 1 min; Teff = .983
Avg. LM = +6.37 FOV Mid period 06hr 30 +13
Mid Period Sol Long. 259.490
Period 2
7:00-8:00UT SPO(4) GEM(14) ANT/XOR(3)
MON(2) HYD(1) Total (24)
Dead time = 1 min; Teff = .983
Avg. LM = +6.55FOV Mid period 07hr 30 +21
Mid Period Sol Long. 259.532
Showers Observed
GEM (32) 07:20(110) +33
MON (4) 06:48(102) +08
ANT/XOR (6) 06:20(095) +23
HYD (4) 08:32(128) +02
COM (0) 11:24(171)+27
PUP (0) 08:24(126) -45
SPO (08)
Magnitude Distribution
P1
SPO (4) +1(1) +3(1) +4(2)
ANT (3) +1(1) +4(1) +5(1)
HYD (3) -1(1) +3(1) +5(1)
MON (2) +3(2)
GEM (18) -5(1) -3(1)-1(1) 0(2) +2(4)
+3(2) +4(3) +5(1) +6(1)
P2
SPO (4) +3(2) +4(3) +5(1)
ANT (3) +3(1) +5(2)
HYD (1) +3(1)
MON (2) +2(1) +4(1)
GEM (14) +2(1) +4(6) +5(5) +6(2)
5 Minute Bins
P1 (6:00 - 7:00 UT)
Bin #GEM's Magnitudes
0600-0605 GEM (1) +4(1)
0605-0610 GEM (1) +2(1)
0610-0615 GEM (3) +2(1) +3(2)
0615-0620 GEM (0)
0620-0625 GEM (1) -5(1)
0625-0630 GEM (3) 0(1) +2(1) +5(1)
0630-0635 GEM (1) +2(1)
0635-0640 GEM (1) 0(1)
0640-0645 GEM (3) -3(1) +3(1) +5(1)
0645-0650 GEM (1) +4(1)
0650-0655 GEM (1) -1(1)
0655-0700 GEM (2) +4(1) +6(1)
P2 (7:00 - 8:00 UT)
Bin #GEM's Magnitudes
0700-0705 GEM (2) +2(2) +4(1)
0705-0710 GEM (4) +4(2) +5(1) +6(1)
0710-0715 GEM (0)
0715-0720 GEM (2) +4(1) +5(1)
0720-0725 GEM (2) +5(1) +6(1)
0725-0730 GEM (0)
0730-0735 GEM (1) +4(1)
0735-0740 GEM (1) +5(1)
0740-0745 GEM (0)
0745-0750 GEM (1) +5(1)
0750-0755 GEM (1) +4(1)
0755-0800 GEM (0)
From: "Javor Kac" <javor.kac@o...>
Date: Sat Dec 11, 2004 11:18 pm
Subject: (meteorobs) Observation December 10/11, 2004 from Slovenia
After being under the low-lying clouds for the whole week I was
eager to observe this Fryday night. I headed for the site where we
held the last Astronomical Youth Camp. At 800-900 m altitude I
passed through the thin layer of clouds and soon saw the stars -
for the first time in weeks! When I arrived to the site I could see the
clouds bellow with reflections of the cities in the valley, but no
perceptible light domes above the clouds.
The meteor numbers were quite high with 46 recorded in two hours
of observations. The dominant shower were of course the Geminids
with 21 members recorded. Other showers were detectable as well.
The sporadic numbers were quite low despite respectable limiting
magnitude, probably because I was not well rested. The best
meteor was a short and slow magnitude +1 Geminid seen just to
the west of the radiant. It left a one-second train.
I had to end the observation because my observing mate (not
observing meteors) almost froze after two hours.
The weather predictions are very good for the Central Europe for the
next few days so I think I will observe more in the following nights.
Clear skies!
Javor
Date: December 10/11 2004
Begin: 22h 19m UT
End: 00h 19m UT
Location: 15?27' 30" E, 46?26' 17" N, 1185 m
Place: Trije kralji, Slovenia (23114)
Observer : Javor Kac (KACJA)
Period (UT) Teff F Lm GEM XOR MON HYD Spor
22:19-23:19 1.00 1.00 6.89 8 1 2 1 8
23:19-00:19 1.00 1.00 6.81 13 0 1 1 11
Magnitude distributions:
GEM: -2(1) -1(0) 0(4) +1(3) +2(3) +3(4) +4(4) +5(1) +6(1)
XOR: +4(1)
MON: +3(1) +4(0) +5(2)
HYD: +2(1) +3(0) +4(0) +5(1)
Spor: +3(4) +4(6) +5(7) +6(2)
Slovenska Bistrica, Slovenia -- 46?3'24N - 15?3'47E - 288m
From: "Bruce McCurdy" <bmccurdy@t...>
Date: Sat Dec 11, 2004 4:25 pm
Subject: (meteorobs) Asymmetric Geminids
Sitting by my computer on a cloudy night, listening to the radio
Geminids coming in at the rate of close to one every two minutes and
spending the down time idly thinking. Look out below.
In one of several highly informative posts, Norman wrote:
> The twist comes right after the time of peak. Rates fall very rapidly
> almost right afterwards, taking only a few hours to lose what required
four
> full days to build up. The activity curve is not symmetrical -- it has a
> disappointing cliff.
I was shocked by this asymmetry last year to the point that I thought my
radio reception might have been poor on the 15th. The drop-off was very
rapid, and very convincing. Here are my hourly radio rates for the 5-hour
window centred on the radiant transiting the local meridian:
UT Avg.
Date | 07 08 09 10 11 | HR
===============================
Dec 11 | 33 24 25 32 26 | 28
Dec 12 | 34 41 43 46 34 | 40
Dec 13 | 80 77 74 73 43 | 69
Dec 14 | 111 97 105 119 81 | 103
Dec 15 | 18 26 22 18 28 | 22
I'll be interested to see if this year's results corroborate this.
Judging from Norman's assertion, they should. I just hope the good reception
keeps up... so far so good.
Several questions: Is there a physical explanation for the asymmetric
distribution of the meteoroid stream? And Norman, could you comment further
on a previous remark you made about the 'expected decline' of the Geminids
in general? Has the stream somehow rippled through Earth's orbit? Finally,
does Earth itself play a role as a 'shepherd' of meteoroid streams in a
manner analogous to what we see in Saturn's F ring?
Don't feel obliged to answer them all. regards, Bruce |
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