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(meteorobs) Observation July 19/20 2002
On the morning of July 20, I decided to head out to the Casselman
site (located south-east of Ottawa) to enjoy a bit of the dark sky
window during the early morning hours. Upon arriving at the site
near midnight, I was greeted by a number of observers who were setup
with scopes. There was still a band of cirrus clouds passing through
so I took my time and enjoyed gabbing with those that were present
there. Once the clouds moved away and the Moon set about 2 hours
later, I signed-on for meteor observing. The sky remained clear
until dawn, with my limiting magnitude averaging over 6.3.
In a little over one hour TEFF, I recorded 9 meteors. There was low
activity coming from several active radiants (including minute
activity from the Sagittarids, North Delta Aquarids, South Delta
Aquarids and the Perseids. There was also a few meteors from the
north apex and a few random sporadics.
My first Perseid of 2002 arrived at 7:29UT. It was a 2nd magnitude
streak in Lacerta that left behind a one second train.
Another highlight was at 7:42UT when a very swift 1st magnitude blue
meteor shot from the north apex source, and left behind a one second
persistent train.
Pierre Martin
Ottawa, Ontario
DATE: July 19/20 2002
BEGIN: 0621 UT (0221 EDT) END: 0755 UT (0355 EDT)
OBSERVER: Pierre Martin (MARPI)
LOCATION: Long: -75.063 West; Lat: 45.079 North Elevation: 50m
City & Province: Casselman, Ontario, CANADA
RECORDING METHOD: talking clock/tape recorder
-----------------------------------------------------------------------
OBSERVED SHOWERS:_______________________________________radiant position
ACY (Alpha Cygnids)_____________________2028 +48
SAG (Sagittarids antihelion source)_____2052 -16
CAP (Alpha Capricornids)________________2000 -12
NDA (North Delta Aquarids)______________2120 -09
SDA (South Delta Aquarids)______________2216 -18
PAU (Pisces Austrinids)_________________2220 -32
PER (Perseids)__________________________0116 +52
napx (sporadics from the north apex)____0152 +26
sapx (sporadics from the south apex)____0152 -04
SPO (random sporadics)
-----------------------------------------------------------------------
OBSERVING PERIODS: 0 = none seen; / = shower not observed
PERIOD(UT)__FIELD____Teff__LM____SPO_PER_ACY_CAP_SAG_NDA_SDA_PAU_napx_sapx
0621-0654___2246+12__0.53__6.36__3___0___0___0___0___1___0___0____0____0
0717-0755___2246+12__0.58__6.21__0___1___0___0___1___0___1___0____2____0
TOTALS:______________1.11________3___1___0___0___1___1___1___0____2____0 = 9
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: +1(1) +2(0) +3(2) +4(1) +5(1) AVE: +3.2
NDA: +1(0) +2(1) +3(0) +4(0) +5(0) AVE: +2.0
SDA: +1(0) +2(0) +3(0) +4(1) +5(0) AVE: +4.0
PER: +1(0) +2(1) +3(0) +4(0) +5(0) AVE: +2.0
SAG: +1(0) +2(1) +3(0) +4(0) +5(0) AVE: +2.0
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:
- 3 minutes used for breaks.
- 1.32 min used for plots.
Breaks (UT): 0627 (1min), 0654-0717, 0743-0745
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