(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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