(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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