[Meteorobs] Observation August 12/13 2009

[Pierre Martin]

On the following day, Ivo and I returned to Westmeath Lookout for  
another full night of observing.  We did another full setup of all our  
equipment.  This time, the weather was excellent... with very good  
transparency and much dryer conditions.  Ground conditions were also  
dry with not even a hint of dew until well after midnight.  There were  
a few mosquitoes out early, but these soon went away later on.  All in  
all, a very comfortable night!  We were excited at the prospect of  
elevated Perseid rates, near maximum activity.

While the previous night was shared mainly with observers we knew  
well, this time, we'd have several members of the public coming by to  
view the meteors (even one family showed up at 2am with their young  
child).  They would not be disappointed.

Despite the low evening radiant, I signed on at 9:45pm EDT, in order  
to enjoy the short window of dark skies before the Quarter Moon would  
rise, just a half hour later.  Overhead, the sky was excellent and the  
Summer Milky Way was impressive.  Just barely a minute going into my  
session, Ivo and I shouted loudly as a beautiful yellow-orange mag -3  
Kappa Cygnid descended into the north.  This impressive first meteor  
crawled for a long 30 degrees, leaving behind a wake.  What a nice way  
to start the night!

It took five minutes before my first Perseid of the night was seen...  
a nice mag +1 meteor that climbed for about 20 degrees.  Then, very  
quickly... two more fainter Perseids were seen.  Now I expected to get  
a lull, as I usually do when the shower radiant is low.  But that was  
not the case.  Just three minutes later, another pair of Perseids,  
including a mag 0 meteor leaving a one second train!  It was apparent  
that the Perseids were already more active than usual.  Very soon,  
Perseids appeared on the average of one per minute, including several  
long and bright earthgrazers (the two best were the vivid mag -2  
yellow-orange meteor at 9:59pm, and a mag -1 blue-white Perseid that  
stretched over 50 degrees at 10:20pm!).  At the end of my first hour,  
I had already logged 37 Perseids, 8 sporadics and 1 Kappa Cygnid.

With the rates looking good, I decided to keep on observing with just  
minimal breaks (dead time) when necessary (as I was running my two  
DSLR cameras on a mount). Interestingly, the second hour produced only  
33 Perseids, despite the radiant gaining some elevation.  The  
moonlight was starting to wash out the sky, so this is not too  
susprising.  But there might have also been a genuine decline in the  
rates, following the traditional peak that occurred several hours  
earlier (in the middle of my afternoon).  Just a few minutes after  
midnight, one of the more impressive Perseids streaked across a long  
30 length of the sky, crossing the zenith, and soon flaring to  
magnitude -3 with a persistent train left glowing for 3 seconds!

The third period (from 12:15-1:25am (exactly one hour effective time)  
exploded with 78 meteors (73 Perseids and 5 sporadics) !!  Things were  
getting busy, and I could feel the rates rising, first gradually, and  
then more sharply near the end of this period.  Within just 3 minutes  
(between 1:22-24am), a burst of 12 (!) Perseids shot out in various  
directions, some of which were quite closely spaced!  Both Ivo and I  
were noticing several fairly bright Perseids scooting by the field of  
view of our three cameras.  The Quarter Moon was definitely becoming a  
pain in the south, but this was minimized by keeping my field of view  
in the north, and using a large umbrella to hide as much of the glare  
as possible.  By doing this, I could acheive semi-dark adaptation and  
still see stars as faint as mag 5.5-6.0 in that area of the sky.

The fourth period (from 1:25-2:40am (also one hour effective time)  
coincided with the peak of a second outburst.  As many as 116 meteors  
were seen (107 Perseids, 8 sporadics and 1 Kappa Cygnid).  With a peak  
appearing about 2:00am EDT, meteors flew right and left, top and  
bottom... WOW!!!  I could feel my heartbeat increasing from the  
adrenaline build-up :)  Sometimes, a pair of meteors would be seen,  
followed by more... it would sometimes be hard to catch up on  
individual descriptions!  The two brightest Perseids in this hour were  
mag -3 beauties with trains lingering for a few seconds.  Lulls were  
also a rarity near the top of the hour - something I have not  
experienced since the Leonids of the early 2000's!  This marked some  
of the finest activity I have ever seen of the Perseids, especially  
considering the moonlit sky.  A very pleasing and impressive display!!!

The fifth period (2:40-3:46am (another hour) saw a sharp decrease in  
observed rates, despite the radiant climbing.  It was clear that the  
outburst was now in its descending slope.  Even so, a very satisfying  
76 meteors were seen (68 Perseids, 6 sporadics and 2 Kappa Cygnids).   
The highlight in this hour was a vivid blue-green mag 0 Perseid that  
flared almost right on top of the radiant.  The foreshortened meteor  
left a bright 3 second persistent train.

The final period (3:46-5:00am (nearly an hour and a quarter) had  
further decreasing rates, with 55 meteors (50 Perseids and 5  
sporadics).  The last half hour had brightening morning twilight, but  
I continued to observe for as long as possible, until my LM dropped  
just below 5.0.  Even in the deep blue sky, and the ground fog slowly  
building up, the Perseids were still quite productive!

At the end, Ivo and I were exhausted from the long night of observing  
and photographing meteors.  It was great to see the public having been  
generally very pleased at their middle-of-the-night outings too.  Ivo  
opted to sleep for a few hours under the shade of the gazebo while I  
brought my chair down the hill and under the shade of a tree.  Just as  
I was wrapping myself in my sleeping bag, I took one more casual  
glance at the sky ... and ... as luck would have it, a Perseid  
fireball was seen streaking across a blue morning sky ending with a  
bright mag -4 terminal flash!  What a way to end a most memorable night!


SUMMARY:  On this night, I logged a total of 409 meteors (368  
Perseids, 37 sporadics and 4 Kappa Cygnids).  The average magnitude of  
Perseids was +2.06 (over half a mag brighter than the sporadic  
background).  What a thrill to witness two separate outbursts from the  
same shower!

Details below...

Pierre Martin
Ottawa, Ontario




DATE: August 12/13 2009
BEGIN: 01:45 UT (21:45 EDT) END: 09:00 UT (05:00 EDT)
OBSERVER: Pierre Martin (MARPI)
LOCATION: Long: -76.859 West; Lat: 45.793 North
Observing site: Westmeath Lookout (White Water Region), Ontario, CANADA
RECORDING METHOD: talking clock/tape recorder, cord align
----------------------------------------------------------

OBSERVED SHOWERS:_______________________________radiant position
KCG (Kappa Cygnids)______________________________18:56 +58
PER (Perseids)___________________________________02:56 +57
SPO (sporadics)
(other showers not watched)
----------------------------------------------------------

OBSERVING PERIODS: 0 = none seen; / = shower not observed

PERIOD(UT)____FIELD_______Teff___F_______LM_____SPO__PER__KCG

01:45-02:51___15:31 +77___1.00___1.00____6.32____8___37___1
02:51-04:15___15:31 +77___1.00___1.00____6.00____5___33___0
04:15-05:25___16:55 +77___1.00___1.00____5.90____5___73___0
05:25-06:40___18:57 +77___1.00___1.00____5.85____8__107___1
06:40-07:46___18:57 +77___1.00___1.00____5.65____6___68___2
07:46-09:00___22:36 +73___1.23___1.00____5.24____5___50___0

TOTALS:___________________6.23___________________37__368__4  =  409


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), where 1.00 is exactly one hour. 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
_____-3__-2__-1___0__+1__+2__+3__+4__+5______AVE

SPO___0___0___0___4___4___6___9__12___2_____+2.73
PER___3___8__15__31__58__73_110__55__15_____+2.06
KCG___1___0___1___0___0___0___1___1___0_____+0.75

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  
(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: 61 min (breaks)

Breaks (UT): 2:05-08, 2:24-27, 3:09-28, 3:49-53, 4:11-12, 4:49-50,  
4:58-5:07, 5:52-53, 6:01-15, 7:12-18

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