(meteorobs) Observation July 30/31 2005

[dob14.5 at sympatico.ca]

On Saturday July 30, the sky looked impressive.  On that evening while enjoying a fireworks show at the casino, at 9:43pm an impressive mag -4 fireball appeared in the south with a terminal flash.  I was surprised to catch this sight despite all the light pollution around us.  After the show, I decided to go straigth for Bootland Farm to get in some meteor observing into the morning hours.  On my way there, I spotted a slow moving, long and very persistent meteor in the north.

The sky at Bootland Farm was impressive.  The Milky Way showed lots of structure all the way down to the southern horizon and it had that "3D" look.  M13, M15 and the North American nebula stood out well naked eye.  The shape of M31 was visible.  I estimated the limiting magnitude near 6.6.  It was a comfortable night too with no mosquitoes.  As I setup, I kept spotting meteors go by in different directions.

Unfortunately, my bad luck with clouds happened again as not 40 minutes into my watch I got suddenly clouded over.  The clouds persisted for a full two hours, as I slept in my chair.  When the sky cleared up again, there was less than 30 minutes before the morning twilight would get too bright.

In a little over one hour teff (effective time) during the clear skies, I got in 21 meteors.  The South Delta Aquarids seemed a little less active, but an increase in sporadics made up for it.

The highlights of the night... at 1:50am EDT, a mag +2 sporadic earthgrazer that shot 50 degrees and left a 2 sec train.  Also memorable was a spectacular slow-moving blue-white Alpha Capricornid at 4:29am... it reached mag -3 and fragmented low in the south.

Pierre Martin
Ottawa, Ontario


DATE: July 30/31 2005
BEGIN: 0520 UT (0120 EDT)  END: 0840 UT (0440 EDT)
OBSERVER: Pierre Martin (MARPI)
LOCATION: Long: -76 29' West; Lat: 45 23' North  Elevation: 200 ft
City & Province: Bootland Farm (near Arnprior) Ontario, CANADA
RECORDING METHOD: talking clock/tape recorder, plotting & cord align
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OBSERVED SHOWERS:_____________________________________radiant position
		CAP (Alpha Capricornids)_________________________20:36 -10
		ANT (anthelions)_________________________________21:28 -14		NDA (N. Delta Aquarids)__________________________21:52 -08
		SIA (S. Iota Aquarids)___________________________21:54 -16
		SDA (S. Delta Aquarids)__________________________22:24 -16
		PAU (Pisces Austrinids)__________________________22:56 -29
		PER (Perseids)___________________________________02:04 +55
		SPO (random sporadics)
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OBSERVING PERIODS: 0 = none seen;  / = shower not observed

PERIOD(UT)_FIELD____Teff__LM_____SPO_CAP_SIA/ANT_NDA_SDA_PAU_PER

0520-0840__2329+12__1.20__6.44____9___4_____2_____0___2___0___4  =  21

*Note: SIA/ANT activity combined together

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).  The next 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.
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MAGNITUDE DISTRIBUTIONS:

SHOWER
______-3__-2__-1___0__+1__+2__+3__+4__+5_____AVE

SPO____0___0___0___0___0___2___1___3___3_____+3.80
CAP____1___0___0___0___1___1___1___0___0_____+0.75
ANT____0___0___0___0___0___0___0___1___1_____+4.50
SDA____0___0___0___0___0___1___0___1___0_____+3.00
PER____0___0___0___0___2___1___1___0___0_____+1.80

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.

SKY OBSCURED (FOV): None

F = 1.00

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Dead time: 128 min (breaks - clouds)

Breaks (UT): 6:00-8:08

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