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(meteorobs) Leonid observations from Pic de Colmaine, Nov 19/20 - narrative - ATAJU
<this is the second post of the same message, the first one hasn't come through
yet. Also I've made some corrections. Sorry if a double post appears. Enjoy!>
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Hi!
I'm quite sure now that I live in the November cloud capitol of Europe. Why?
Get this: Leo97 cloudy, Leo98 clear, Leo99 cloudy, Leo00 cloudy, Leo01 cloudy,
Leo02 cloudy. Beginning to see a pattern here? Javor, Jure and I decided quite a
long time ago that we would observe this year's Leonids from Spain. Booked
flights, rented cars, pretty much did everything, just to cancel everything due
to a bad medium range weather forecast. Back to square one. Rent a van, wait for
the last minute and drive to whereever necessary. We were joined by three other
observers: Nina, Dunja and Daniel. In the morning of Nov 18th we set out for
what would be a 900 km drive to Nice in France. Werfried Kuneth voulenteered as
'mission control', passing us weather info via mobile phone every 30 minutes.
Thanks Werfried!! We reached Nice around 21h UT and the monotonous cloud cover
that had been present for most of the drive began to break in places. Clouds
were relatively low and we could see that there wasn't any high cloud cover
above it.
We then decided to turn north towards the Alps, the mountain village of St.
Martin-Vesubie seemed a good destination with about 1500m altitude. After an
hour's drive the sky we reached St. Martin. It was absolutely magnificent: the
snow covered peaks bathed in moonlight and a completely clear sky! But the
horizon was a bit less satisfying - reaching as high as 40 degrees in the north.
After about an hour's search we found a suitable observing spot on a ski slope
on Pic de Colmaine.
As soon as I stepped out of the car (22:55UT), a blue -3m sporadic fireball
shot through Ursa Major. We then proceeded to set up our equipment: all-sky
camera, photo camera battery and visual stuff. Midway through preparations a -5m
green Taurid appeared in the northwest. Now it was Murphy's time to join us.
First the camera battery shutter failed. We couldn't isolate the problem, let
alone fix it. Then the all-sky camera mirror (60 cm diameter acrylic glass)
began to dew and then frost. All-sky was soon history. Javor then mounted his
Mintron camera on a photo tripod - guess what, it worked! Then the sky suddenly
lit up as a brilliant green -12m Taurid fireball exploded in the zentih,
producing a shower of orange fragments. Everything was going just fine (ignoring
all the failed equipment) when... FOG began to form just around our altitude. In
a matter of minutes most of the sky was covered and we were in despair! Javor,
Dani and I decided to walk (or rather climb!) the steep ski slope to the peak
and see if there was any chance of clear skies in the vicinity. 10 minutes and a
gallon of sweat later we were at the peak (1790m). There was a cottage at the
top with a large viewing platform. The sky was clear - the fog was below us. We
quickly ran down to get our equipment. The fog disapeared in the meantime. Also
a 50 degrees long -3m Leonid fireball shot through Auriga. Even though it was
clear when we reached the van, we rather walked to the peak again, just in case
fog returned. It didn't. The peak was covered with grass and rocks. The snow
line was several hundreds of meters above us.
I started observations at 01:18 UT. I was facing east towards Ursa Major and
Lynx, with the cottage several tens of meters behind me. With the Moon well out
of my FOV the LM was very good at 5.8. There was just a slight breeze. As usual
I began observing outside my sleeping bag, but the low temperatures (-5C or
less) forced me to crawl into the bag rather soon. Leonids were immediately
apparent, coming at a rate of about one per minute. Javor and Jure Z began
making exposures. A little later, at 2:16:38 UT, just after Jure had filed a
formal complaint about the lack of fireballs a green -6m Leonid shot through
Ursa Major, right throught his photographic FOV. He was *quite* happy with that
(you should listen to the tapes...). Another -3m Leonid appeared at 2:32 UT. By
then the Leonids were coming at a rate of two or three per minute. Another -3m
Leonid at 2:45. We had a minor incursion by fog for three minutes starting at
2:55, lowering the LM by .5 mag. Then at 03:00:03 UT the northern sky lit up as
a brilliant -10m green Leonid exploded near Denebola, leaving a vividly green
train, that would persist in bright moonlignt for more than 9 minutes.
The third hour started at 3:18 UT. With 4 Leo per minute the show was nice,
but I was beginning to wonder if perhaps it was running behing schedule or below
predictions. Also the Leonids were much fainter than last year, negative
magnitude shower members were rare. The rate was slowly rising, by 3:30 UT -
only 30 min before the predicted peak - there were 5 per minute. By 3:40 UT the
rate had sharply increased to 15 per minute. A -3m Leo fireball in Orion at
3:40:59 left a 48 second train. By 3:50 the rate increased modestly to 18 Leo
per minute. 4:00 UT and there were 25 per minute. A spike in rates was reached
at 4:04 with 47 Leo per min, flanked by lower rates of 30 and 32 Leo per min.
For the next seven minutes the rates hovered around 30 per minute. The peak was
reached around 4:12 UT with rates above 40 Leonids per minute for four minutes
(top rate 46 per minute). I managed to record magnitudes all the way to the
peak. Then I didn't record for four minutes AFTER the peak, when I though I
couldn't keep up if the rates kept increasing. So, there is one minute with a
meager 19 Leonids with no magnitude data. You idiot... Only one fireball
appeared in this time, a -3m Leo at 4:00. All this time there were very few
bright Leonids. Most were +2m to +4m. Many short Leonids appeared near the
radiant. Brighter Leonids that were close to the radiant often left a 'thick'
greenish train that *immediately* went serpentine. I wonder if this effect is
present also with trains of longer meteors further away from the radiant, but is
not visible because we see the trains more perpendicularly?
By 4:30 the Leonid rates had diminished to 12 per minute. 15 minutes later
there were about 8 per minute. At 04:49:00 another -10m Leonid, this time
orange, appeared in the northwest, followed by a -4m Leonid only 4 seconds
later. For the rest of official observations, until 5:16 UT the rates remained
above 4 per minute. LM was 6.0 for the final 30 minutes. Two more bright flashes
were seen. We remained at the top of the mountain for another half hour. Javor
and Jure made some nice pictures of the breathtaking surrounding landscape. I
kept looking in the sky :) And I saw two more -5m Leonids.
Leonids 2002? Oh yeah! Definitely excellent. We had luck with the weather and
found perfect skies. The rates were excellent. Compared to 2001 7-rev peak, this
year the peak was much shorter and sharper and the meteors much fainter. Inital
ZHR calculations by our team suggest top ZHR 3300 and FWHM of only 40 minutes.
My magnitude data suggests r=2.6, while that of Jure and Javor suggests r=2.4.
In 3.95h teff I saw a grand total of 1775 Leonids, 1 Alpha Monocerotid, 2
Taurids and 12 sporadics.
Clear skies!
Jure A.
MBK Team / AS Orion
www.orion-drustvodot si/MBKTeam
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