(meteorobs) Observation August 2/3 2009

Pierre Martin dob14.5 at sympatico.ca
Sun Aug 9 19:14:30 EDT 2009


Here's my observation for Monday morning August 3.  I had one more  
shot at the dark moonless window for a short 35 minute period before  
dawn.  The sky on this night was quite transparent and even the Milky  
Way showed faintly, so I decided to start observing while the bright  
gibbous Moon (only two days before Full) was still low in the west.

I went to the Moosecreek site (east of Ottawa) to join a few observers  
who came to setup their telescopes at 2:00am, also to catch the brief  
moonless window before dawn.  Present was Jim Sofia with an 18"  
Obsession Dob, Remsy with a Skywatcher 12" truss Dob and Christo.   
While waiting for the Moon to descend, I enjoyed some sharp views of  
Jupiter in Jim's scope.  It was interesting to see all four major  
satellites well away from the planet, while at the same time, we could  
see a deep dark round feature in the center of the planet!  After some  
initial confusion/excitement, we realized what was happening... Io was  
transiting Jupiter (causing a dark shadow) while the "extra" moon was  
in fact the 5.9 mag star 45 Capricorni, which happened to be  
positioned perfectly along the plane of Jupiter ;)

I signed on for meteors at 2:30am EDT, and observed for exactly two  
hours until the morning twilight became too bright.  The changing sky  
conditions (Moon, morning twilight) meant that I had to estimate the  
limiting magnitude quite often, usually once every 15 minutes.  The  
sky was significantly brighter during the first hour due to the Moon  
setting in the west, however the LM averaged at a respectable 6.06.   
After moonset, the LM reached 6.43, which lasted for about 35 minutes,  
after which morning twilight gradually brightened the sky.

During those two hours, I saw 40 meteors.  The Perseids were clearly  
getting more active - dominating all shower activity and even matching  
the sporadic background.  The Delta Aquarids produced only a few  
meteors, and I managed to see a couple of early Kappa Cygnids.

The brightest meteor was a mag -1 blue Perseid with a 1 second train.

Pierre Martin
Ottawa, Ontario



DATE: August 2/3 2009
BEGIN: 06:30 UT (02:30 EDT) END: 08:32 UT (04:32 EDT)
OBSERVER: Pierre Martin (MARPI)
LOCATION: Long: -75.063 West; Lat: 45.269 North
Observing site: Moosecreek, Ontario, CANADA
RECORDING METHOD: talking clock/tape recorder, cord align
----------------------------------------------------------

OBSERVED SHOWERS:_______________________________radiant position
KCG (Kappa Cygnids)______________________________18:52 +58
CAP (Alpha Capricornids)_________________________20:40 -08
ANT (Antihelion)_________________________________21:24 -13
SDA (South Delta Aquarids)_______________________22:48 -15
PAU (Pisces Austrinids)__________________________23:00 -28
PER (Perseids)___________________________________02:12 +55
SPO (sporadics)
----------------------------------------------------------

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

PERIOD(UT)____FIELD_______Teff____LM____SPO_PER_SDA_CAP_ANT_PAU_KCG

06:30-07:30___22:35 +05___1.00___6.06____8___6___2___0___2___0___1
07:30-08:32___23:40 +05___1.00___6.18____8__10___2___0___0___0___1

TOTALS:___________________2.00__________16__16___4___0___2___0___2  =   
40


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
_____-1___0__+1__+2__+3__+4__+5______AVE

SPO___0___1___2___4___4___5___1_____+2.94
PER___1___2___2___2___4___4___0_____+2.06
SDA___0___1___1___1___1___0___0_____+1.50
ANT___0___0___0___0___0___2___0_____+4.00
KCG___0___0___0___0___0___2___0_____+4.00

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  
(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: 2 min (break)

Breaks (UT): 7:57-59




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