(meteorobs) Observation August 12/13 2007 (Otter Lake)
Pierre Martin
dob14.5 at sympatico.ca
Fri Oct 12 01:23:21 EDT 2007
I was planing to watch and photograph the night of the Perseid
maximum with fellow observer Ivo Leupi. Cloudy skies ruled the
daytime, and things did not look promising, but a cold front was
slowly approaching from the north. I remained hopeful. By mid-
evening, Ivo Leupi, Shane Finnigan and I chose to drive to dark skies
north of Ottawa. After an hour and a half on the road, we arrived at
our destination near midnight. The overcast skies started to break,
which was encouraging. Shane, Ivo and I spent the next several
minutes watching the sucker holes... and catching the occasional
Perseid going through! It was obvious that some interesting activity
was going on behind the cloud cover. Shane's 10 year old son watched
and at one point said.. "hey, that one looked like a bug!".
The skies eventually showed a clearing trend, so Ivo and I proceeded
to setup our camera equipment out in a large open field. We had lots
of equipment to bring out into the field, which took a while - but it
was worth it.
The very dark LM 6.8 skies were spectacular!!! The Milky Way was
gloriously detailed, and M33 was distinctly visible to the unaided
eye. The transparency was of excellent (5/5) quality and the air was
very dry. Many faint stars were sparkling, even very low near the
horizon - where sky glow and airglow seemed to be at a minimum. The
zodiacal band was visible, and M31 revealed its unmistakable shape to
the unaided eye. One could not ask for a better night... That was
until the patchy low cumulus clouds started moving through again just
minutes later :0( For the rest of the night, I was forced to sign-
off for a long length of time as I waited (and hoped) for the clouds
to go by. In the meantime, the available sucker holes provided
scores of Perseids. Eventually, I was able to resume observations
with 20% or less cloud obstructions in my field of view. By then,
the night was almost over.
Out of one effective hour TEFF, I recorded 78 meteors (of which
included 60 Perseids). The impression I had of this year's Perseids
was a rather normal (maybe even a bit lower than usual) peak of
activity, with nothing really out of the ordinary. The rates were
irregular... there were some busy instances of a small handful of
meteors going by, followed by several minutes of inactivity. The
Perseids were surprisingly difficult to photograph too (I had far
better luck with last year's Orionids and Geminids). No fireballs
were seen either.
The meteor highlight came at 2:11am EDT when a mag -1 Perseid shot a
40 degrees path, ending in a terminal flash, and leaving behind a 2
sec train.
In the morning dawn, Ivo and I packed our stuff and went for a two
hours snooze before heading back home. The cloud cover was a
nuisance and limited available TEFF to just one hour. On the other
hand, the clear periods were spectacular!
Pierre Martin
Ottawa, Ontario
DATE: August 12/13 2007
BEGIN: 0550 UT (0150 EDT) END: 0844 UT (0444 EDT)
OBSERVER: Pierre Martin (MARPI)
LOCATION: Long: -76.50 West; Lat: 46.00 North Elevation: 200 ft
City & Province: Otter Lake, Quebec, CANADA
RECORDING METHOD: talking clock/tape recorder, cord align
----------------------------------------------------------
OBSERVED SHOWERS:_______________________________radiant position
PER (Perseids)____________________________________03:04 +58
CAP (Alpha Capricornids)__________________________21:20 -05
ANT (Antihelions)_________________________________22:08 -09
SDA (South Delta Aquarids)________________________23:20 -13
KCG (Kappa Cygnids)_______________________________18:52 +58
SPO (sporadics)
----------------------------------------------------------
OBSERVING PERIODS: 0 = none seen; / = shower not observed
PERIOD(UT)___FIELD____Teff____F______LM___SPO_PER_CAP_ANT_SDA_KCG
0550-0844___0430+69___1.14___1.18___6.83___15__60__0___2___1___0
Note: The first column (Period UT) refers to observing periods broken
down as close as possible to one hour of true observing, 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) represents
effective observing time (corrected for breaks or any time not spent
looking at the sky). The column (LM) is the average naked eye
limiting magnitude, determined by triangle star counts. All following
columns indicate the number of meteors for each shower observed.
------------------------
MAGNITUDE DISTRIBUTIONS:
SHOWER
______-1___0__+1__+2__+3__+4__+5______AVE
PER____3___4___6__13__18___9___7_____+2.57
SPO____0___0___1___2___5___5___2_____+3.33
ANT____0___0___1___0___0___1___0_____+2.50
SDA____0___0___0___0___1___0___0_____+3.00
Note: 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. The above table contains the magnitudes from all observed
meteors, and the average (last column) for showers.
------------------------
SKY OBSCURED (FOV) (UT): None
------------------------
Dead time: 105.5 min (breaks due to cloud cover)
Breaks (UT): 6:05 (30 sec), 6:25-7:28, 7:37-8:15, 8:28-32
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