(meteorobs) Observation December 13/14 2009 + images
Pierre Martin
pmartin at teksavvy.com
Sun Aug 8 02:16:06 EDT 2010
For the Geminids peak night, Ivo Leupi and I were determined to travel
where we could watch all night under clear skies. We first
contemplated driving several hours out of Ottawa, but we then chose to
stay a bit more local due to unstable weather systems. The short term
forecasts predicted a clearing sky to the north-west of Ottawa. We
hit the road as early as possible after we had some supper, and drove
north towards Maniwaki. Road conditions were awful, with lots of
slush, occasional snow flurries, road spray and reduced visibility.
It got better the further north we got, although the sky was solidly
overcast. Some 160km of driving distance later, we reached Montcerf
and began looking for a quiet, and reasonably dark spot with decent
horizons. It took less than half an hour to find one... a nice dead
end spot that was completely quiet and dark. With the sky still
overcast above, we started setting up the camera equipment - figuring
that the clearing was on its way. Unfortunately, this was not meant
to happen. After waiting until 11pm, we decided to pack and hit the
road again - perhaps the clearing had stalled? We looked at our
options, and studied the map. We did not have a way to look up the
current weather forecast. We opted to drive as far west as we could,
in a bid to reach the clear skies that had been forecasted earlier in
the day. So we drove some two hours (75km) west of Maniwaki on
nothing but a snow-covered loggers road called "Rang de l'Aigle". It
was passable, provided we didn't stop in some of the more snow covered
areas. Eventually, this route became known simply as "unmarked road"
on our GPS. We drove with absolutely nothing but forest all around
us, and no signs of clear skies. We took note of any possible areas
we could setup next to the road (there were almost none). As you can
see with the image below, the back of the car looked more like an
igloo as it accumulated thick layers, of snow that'd get kicked up
behind the tires. We occasionally had to stop to clear up the
windows...
http://tinyurl.com/3azlyvm
Just as we were losing hopes of seeing any Geminids, near 2:00am local
time we finally spotted a few stars near the horizon, and quickly the
clouds were beginning to break up. A couple of meteors seen going
down. We stopped the car as we noticed a good sized "sucker hole"
above us. We sure didn't want to miss it! Not a moment after
stepping out, a gorgeous mag -4 Geminid fireball flashed high up,
followed by three other meteors. Our very remote location allowed an
inky black mag 7+ sky overhead, where it was clear. Orion was buried
in a sea of faint stars. We casually enjoyed the view, but we had no
space to setup... and remaining on the narrow road could be dangerous,
should an unsuspecting logger's truck come barreling in. Judging by
the cloud movement, we chose to drive back to a spot on the side of
the road that we knew would work and be safe. The clearing seemed to
be heading in that direction. This meant that we needed to drive an
hour back where we came from to reach that spot. Once we finally got
there, we were gratified to find that the sky was indeed clearing. It
was now past 3am. We rushed to setup the equipment. Overhead, we
could see meteors going by every few moments. Suddenly, the entire
sky (and ground) lit up as a mag -9 sporadic fireball came out of
nowhere and shot like a lightning bolt across the southern
constellations! It left behind a long and incredibly bright blue-
green persistent train, that glowed at about mag -3 for several
seconds, before gradually fading and twisting apart over the course of
the next 240 seconds. Wow! It was not until a few days later that I
realized that one of our cameras was able to capture (by chance) the
faint remnants of this train as much as 30 minutes later! We rushed
to start the cameras and get on with observing, but the cold night
only added to the setup time (i.e. handling equipment with thick
gloves and all).
Ivo and I bundled up in our lawn chairs. Sky was average transparency
with LM=6.6. I signed on at 3:40am, but observed for only 17 minutes
before more clouds moved in. Yet this short amount of time was very
active with 26 Geminids, including some instances of meteors appearing
a split second apart. The clouds forced me to stop for close to an
hour and half. Ivo went for a snooze while I kept casual watch. At
4:49am, a bright blue mag -5(?) or so Geminid fireball surprised me,
seen through thick cloud cover, followed just four minutes later by a
mag -3(?) Geminid. The clouds finally parted at 5:20am, and I was
able to observe for over an hour until the morning twilight. Despite
the lower altitude of the radiant at that point, I saw 69 Geminids, 14
sporadics and one Sigma Hydrid. It was not the Geminids "marathon" I
was hoping to acheive, but I was pleased that we managed to see
something despite the challenging weather conditions. My total for
the night (only about an hour and half of watching) is 120 meteors.
The Geminids sure are great!
The following composite of meteors was produced with a Canon 30D and a
16-35mm lens at f/2.8. Five Geminids were captured. Note the very
faint trace of the persistent train (left behind by the mag -9 SPO
fireball about 30 minutes earlier) just below Castor and Pollux...
http://tinyurl.com/2aarepz
Composite of meteors captured with a Canon 20D and a 35mm lens at f/
2.0. This camera managed to capture two bright Geminids in Ursa
Major...
http://tinyurl.com/2fqpyy4
Here's our setup the next morning. Temperature was -17C (1F). Ivo
took this picture while I was still sound asleep, all bundled inside
my sleeping bag...
http://tinyurl.com/2utwxlo
Pierre Martin
Ottawa, Ontario
DATE: December 13/14 2009
BEGIN: 08:40 UT (03:40 EST) END: 11:35 UT (06:35 EDT)
OBSERVER: Pierre Martin (MARPI)
LOCATION: Long: -76 13' West; Lat: 46 26' North
Observing site: Chemin de l'aigle, Maniwaki, Quebec, CANADA
RECORDING METHOD: talking clock/tape recorder, cord align
----------------------------------------------------------
OBSERVED SHOWERS:_______________________________radiant position
MON (Monocerotids)_______________________________06:52 (103) +07
GEM (Geminids)___________________________________07:33 (113) +32
HYD (Sigma Hydrids)______________________________08:42 (130) +01
DLM (December Leonis Minorids)___________________10:22 (155) +34
COM (Coma Berenicids)____________________________11:30 (173) +18
DAD (Alpha Draconids)____________________________14:00 (210) +58
ANT (Antihelion)_________________________________06:16 (094) +23
SPO (sporadics)
----------------------------------------------------------
OBSERVING PERIODS: 0 = none seen; / = shower not observed
PERIOD(UT)____FIELD_______Teff____LM_____SPO_GEM_MON_HYD_DLM_COM_DAD_ANT
08:40-08:57___07:03 +14___0.283___6.60___9___26___0___1___0___0___0___0
10:20-11:35___08:27 +12___1.130___6.33___14__69___0___1___0___0___0___0
TOTALS
:___________________1.413__________23__95___0___2___0___0___0___0 = 120
Notes: The first column (Period UT) refers to observing periods, in
Universal Time. The second column (Field) is the area in in the sky
where I centered my field of view. The third column (TEFF) Teff is
simply the total time during the observing session spent actually
watching the sky. Breaks and/or dead time are not included in the
reported Teff. It is reported in decimal format such that a 60 minute
observing session would be reported as Teff = 1.00. The column (LM)
is the average naked eye limiting magnitude seen. All following
columns indicate the number of meteors for each shower observed. For
more info, see:http://www.namnmeteors.org/guidechap2.html
------------------------
MAGNITUDE DISTRIBUTIONS:
SHOWER
______-2__-1___0__+1__+2__+3__+4__+5______AVE
GEM____1___6___9__13__15__24__21___6_____+2.33
HYD____0___1___2___0___3___5__10___2_____+3.04
SPO____0___0___0___0___0___1___1___0_____+3.50
Notes: Magnitude -8 is comparable to a quarter moon, magnitude -4 with
the planet Venus, magnitude -1 with the brightest star Sirius,
magnitude +2 to +3 with most average naked eye stars and magnitude +6
to +7 are the faintest stars the naked eye can see under typical dark
conditions. A meteor of at least magnitude -3 is considered a fireball
(IMO definition). The above table contains the magnitudes from all
observed meteors, and the average (last column) for showers.
------------------------
SKY OBSCURED (FOV) (UT): None
------------------------
Dead time: 7.15 min (breaks)
Breaks (UT): 8:57-10:20, 10:33 (20 sec), 10:31 (40 sec), 10:34 (20
sec), 10:47 (20 sec), 11:11 (30 sec), 11:12-17
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