(meteorobs) Observation July 30/31 2008

[Pierre Martin]

After a series of late day thundershowers, the sky cleared nicely in  
the predawn hours of Thursday July 31.  The west-end of the city was  
favored, so I decided to head to Bootland Farm.

The night was humid, but a breeze developed to keep dew and fog under  
control.  Mosquitoes were more of a pest on this night, so my  
Thermacell came in handy (what a great device!).  Additional help  
against the bugs was provided by a bat that kept flying low above me  
- so his presence was welcome :0)  Overhead, the sky had a couple of  
very small cloud patches, but these dissipated and the transparency  
eventually became an impressive 4/5 late into the night (limit mag  
about 6.5).  For much of the night, the sky flashed brightly from  
what must have been a sizeable t-storm just below the horizon.  It  
was quite something to see these lightning flashes even under 100%  
clear skies.

Well, what a night!!!  A total of 108 meteors in just over 3 hours!   
My first period (lasting 1 hour) was quite normal, but the rest of  
the night had skyrocketing rates!  I'll have to look back at my  
previous reports, but I don't recall having ever seen so many  
sporadics per hour.  I had 22 (!) sporadics in the second period  
(which lasted exactly one hour), and 24 for the third period (which  
lasted about an hour and 20 minutes).  Meteors were flying from left  
to right, and up and down, with a good number seeming to come out of  
the apex source in the east.  Even the Perseids seemed a bit high on  
this night with 16 of them in the third period.

Although no fireballs were seen, there was a couple of interesting  
events.  At 2:05am EDT, a pair of meteors were seen simultaneously in  
the same area of the sky... a sporadic and a Delta Aquarid, moving in  
different directions.  Had they been closer together, they would have  
probably crossed paths!  Also, at 3:57am EDT, an impressive +2 mag  
sporadic earthgrazer appeared.  It shot 60 degrees of the sky,  
passing high up across the zenith.

Pierre Martin
Ottawa, Ontario


DATE: July 30/31 2008
BEGIN: 0440 UT (0040 EDT) END: 0820 UT (0420 EDT)
OBSERVER: Pierre Martin (MARPI)
LOCATION: Long: -76 29' West; Lat: 45 23' North Elevation: 400 ft
City & Province: Bootland Farm, Ontario, CANADA
RECORDING METHOD: talking clock/tape recorder, cord align
----------------------------------------------------------

OBSERVED SHOWERS:_______________________________radiant position
SDA (Delta Aquarids)______________________________22:36 -16
CAP (Alpha Capricornids)__________________________20:20 -11
ANT (Antihelions)_________________________________21:08 -15
PAU (Pisces Austrinids)___________________________22:44 -30
PER (Perseids)____________________________________01:40 +53
ACY (Alpha Cygnids)_______________________________20:40 +50
SPO (sporadics)
----------------------------------------------------------

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

PERIOD(UT)___FIELD____Teff____F______LM____SPO_SDA_CAP_ANT_PAU_PER_ACY

0440-0544___2041+14___1.01___1.03___6.50____9___7___3___0___0___1___0
0544-0656___2203+10___1.00___1.00___6.54___22___6___1___3___0___8___0
0656-0820___2313+10___1.35___1.00___6.54___24___5___1___2___0__16___0

TOTALS:_______________3.36_________________55__18___5___5___0__25___0  = 
  108

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). 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___1___3___7__14___9__18___3_____+2.69
PER___0___0___3___6___6___4___6_____+3.16
SDA___0___0___1___3___5___5___4_____+3.44
CAP___0___1___2___1___0___0___1_____+1.80
ANT___0___0___0___2___0___3___0_____+3.20

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. The above table contains the magnitudes from all observed  
meteors, and the average (last column) for showers.
------------------------

SKY OBSCURED (FOV) (UT): 10% from 4:57-5:02, 10% from 5:37-5:45

------------------------

Dead time: 18.5 min (incl breaks time)

Breaks (UT): 5:11-14, 5:21 (30sec), 5:45-57, 7:05-08