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(meteorobs) Observation August 11/12 2002
On the evening of August 11, I drove out to the site north of Cobden
(west of Ottawa). It was a big success! Despite considerable haze
in the evening sky, and a threatening thunderstorm cell, the sky
cleared beautifully near 11pm local time. The transparency was very
good with crisp clear skies for the rest of the night. My limiting
magnitude was around 6.50. I took several breaks during this session
as I was operating an unguided camera for most of the night.
This night had myriads of meteors... In almost 5 hours teff, I
recorded 259 meteors (including 208 Perseids, 5 Delta Aquarids, 2
Kappa Cygnids, 2 Capricornids, 2 antihelions and 40 sporadics).
The Perseids were better than I expected. The fourth hour produced a
surge of as many as 64 Perseids! There was five instances when two
meteors would go by almost simultaneously. The Perseids also
produced many very faint meteors (in the +4 to +5 mag range) with an
occasional bright one thrown in. If it wasn't for the strong
Perseids rates, the relatively low activity from other sources would
have made it a slow night. This night really appeared to go by too
quickly ;>
Among the highlights...
At 3:33UT, a long 30 degrees faint sporadic of mag +4 flared twice on its path.
At 7:31UT, a pair of Peseids shoot both simultaneously in different
directions. One of magnitude +2 and other +3.
At 7:38UT, a "point" (or head-on) meteor that defined the Perseid
radiant! It appeared a bright (mag 0) blue flash without any apparent
motion. Then, a tiny (0.5 deg) train was visible for one second.
At 7:40UT, a spectacular Perseid fireball shoots down into Perseus.
It explodes in a dazzling magnitude -5 blue flash. It leaves behind
a persistent train glowing and twisting for as much as 15 long
seconds!
Pierre Martin
Ottawa, Ontario
DATE: August 11/12 2002
BEGIN: 0300 UT (2300 EDT) END: 0840 UT (0440 EDT)
OBSERVER: Pierre Martin (MARPI)
LOCATION: Long: -76.88 West; Lat: 45.63 North Elevation: 50m
City & Province: Cobden, Ontario, CANADA
RECORDING METHOD: talking clock/tape recorder --> cord alignment method
-----------------------------------------------------------------------
OBSERVED SHOWERS:_______________________________________radiant position
KCG (Kappa Cygnids)_____________________1856 +58
CAP (Alpha Capricornids)________________2116 -06
ANT (antihelion source)_________________2212 -10
NDA (North Delta Aquarids)______________2224 -05
SDA (South Delta Aquarids)______________2316 -13
PAU (Pisces Austrinids)_________________2332 -26
PER (Perseids)__________________________0304 +58
napx (sporadics from the north apex)____0312 +32
sapx (sporadics from the south apex)____0312 +02
SPO (random sporadics)
-----------------------------------------------------------------------
OBSERVING PERIODS: 0 = none seen; / = shower not observed
PERIOD(UT)__FIELD____Teff__LM____SPO_PER_KCG_CAP_ANT_NDA_SDA_PAU_napx_sapx
0300-0433___2358+51__1.00__6.41___5__22__1___1___0___0___1___0____1____0
0433-0534___0037+53__1.00__6.50___4__30__1___1___2___0___0___0____2____0
0534-0646___0138+48__1.00__6.50___3__43__0___0___0___1___1___0____0____1
0646-0747___0350+71__0.99__6.50__11__64__0___0___0___0___1___0____1____3
0747-0840___0350+71__0.87__6.37___6__49__0___0___0___1___0___0____2____1
TOTALS:______________4.86________29__208_2___2___2___2___3___0____6____5 = 259
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 I did not
spent looking at the sky). One hour = 1.00 teff. The fourth column
(LM) is the average naked eye limitimg magnitude, determined by
triangle star counts. All following columns indicate the number of
meteors for each shower observed.
------------------------
MAGNITUDE DISTRIBUTIONS:
SHOWER
SPO: -3(1) -2(0) -1(0) 0(0) +1(00) +2(06) +3(05) +4(15) +5(13) +6(0) AVE: +3.72
PER: -3(0) -2(0) -1(3) 0(6) +1(20) +2(43) +3(54) +4(45) +5(35) +6(1) AVE: +2.99
SDA: -3(0) -2(0) -1(0) 0(0) +1(00) +2(02) +3(00) +4(01) +5(00) +6(0) AVE: +2.66
NDA: -3(0) -2(0) -1(0) 0(0) +1(00) +2(00) +3(00) +4(02) +5(00) +6(0) AVE: +4.0
KCG: -3(0) -2(0) -1(0) 0(0) +1(00) +2(00) +3(00) +4(00) +5(02) +6(0) AVE: +5.0
CAP: -3(0) -2(0) -1(0) 0(0) +1(00) +2(02) +3(00) +4(00) +5(00) +6(0) AVE: +2.0
ANT: -3(0) -2(0) -1(0) 0(0) +1(00) +2(00) +3(00) +4(01) +5(01) +6(0) AVE: +4.5
** Note: A Perseid of magnitude -5 was also seen **
Note: Magnitude scale is to determine the brightness of sky objects.
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:
None
Corresponding F value for this session is 1.00
------------------------
Dead time:
- 48.23 minutes used for breaks.
- 0 minutes used for plots.
Breaks (UT): 0306-0323, 0336 (20sec), 0358-0414, 0506 (20sec), 0520
(20sec), 0538 (20sec), 0543 (15sec), 0557-0558, 0611 (15sec),
0623-0633, 0654 (30sec), 0725 (10sec), 0735 (45sec), 0754 (20sec),
0805 (15sec), 0815 (15sec), 0827 (10sec)
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