(meteorobs) Observation July 30/31 2011

Pierre Martin pmartin at teksavvy.com
Wed Aug 10 01:35:18 EDT 2011

The second day at the Irvine Lake airstrip got busier with as many as  
12 observers arriving on site throughout the day with a variety of  
telescopes and astro-imaging equipment.  Sanjeev returned in the  
evening from a visit to Toronto, having left his tripod and mount  
covered from the previous night.  It felt like a small star party.   
Here's a few snapshots that I took during the day:

To help with the high heat of the daytime, we'd relax under the much  
needed shade that Joe Silverman had setup.  Even though this location  
is very remote and had no facilities whatsoever, the food supplies and  
BBQ's were far from lacking.  We made a discovery that the swarms of  
grasshoppers all over the ground would eventually cling to tents and  
chew through the screens!  It was rather disheartening to see this  
kind of damage on some of the expensive tents that were setup.  I had  
no idea that a seemingly innocent grasshopper could do that kind of  
damage.  The day went by quite fast, chatting, enjoying solar  
observing, eating and then taking a late afternoon snooze.

The second night had significantly better transparency, a solid 3/5.   
The mosquitoes came out in furious numbers at dusk but quickly  
disappeared as the temperature cooled.  The wind was calm so it also  
meant that it would be quite dewy too.  I now keep my sleeping bag in  
a waterproof bivy sack which keeps it nice and dry through the entire  
night.  Overhead, the Milky Way was impressive with dust lanes and  
structure visible all the way to the southern horizon.

I started recording meteors just after 11pm EDT.  For the next four  
hours and 40 minutes, I saw 116 meteors.  The Delta Aquarids were  
again the most significant shower activity with 27 seen, followed  
fairly closely by the Perseids with 21 seen.  The most impressive  
meteor was a flaring yellowish mag -1 Alpha Capricornid seen at 3:15am  
EDT.  Another memorable event was seeing two meteors at 2:49am EDT, a  
sporadic and a Perseid, appearing at once, nearly crossing paths!  At  
some point during the night, Graham came and joined me to casually  
view meteors in a huge portable hammock.  I was impressed at Graham's  
ability to perceive very dim and swift meteors almost continuously in  
various parts of the sky.  He blew me away on that... He would very  
clearly see all kinds of swift 5th mag meteors that I'd miss.  I knew  
that he wasn't making things up, because I'd occasionally see a "hint"  
of a something off the corner of my eye when he'd clearly call it.

Pierre Martin
Ottawa, Ontario

DATE: July 30/31 2011
BEGIN: 03:10 UT (23:10 EDT) END: 08:20 UT (04:20 EDT)
OBSERVER: Pierre Martin (MARPI)
LOCATION: Long: -77 15' West; Lat: 45 1' North Elevation: 800 ft
City & Province: Irvine Lake Airstrip (near Denbigh), Ontario, CANADA
RECORDING METHOD: talking clock/tape recorder, plotting

OBSERVED SHOWERS:_______________________________radiant position

PER (Perseids)__________________________________01:58 +54
CAP (Alpha Capricornids)________________________20:22 -10
ANT (Antihelions)_______________________________21:20 -14
SDA (South Delta Aquarids)______________________22:45 -16
PAU (Pisces Austrinids)_________________________22:56 -29
AUP (August Piscids - IMO video database)_______00:30 +18
SPO (sporadics)

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


03:10-04:10__284 +06___1.00___7.00___7___3___1___2___/___2___0
04:10-05:22__298 +02___1.00___7.00__15___6___3___2___0___5___0
05:22-06:29__313 +01___1.00___6.90___9___9___1___3___0___6___0
06:29-07:29__329 +02___1.00___6.78__11___5___1___2___0___8___0
07:29-08:20__350 +12___0.68___6.58__10___4___0___1___0___0___0

TOTALS:________________4.68_________52__27___6__10___0__21___0  = 116

Notes: The first column (Period UT) refers to observing periods, 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) Teff is  
simply the total time during the observing session spent actually  
watching the sky. Breaks and/or dead time are not included in the  
reported Teff. It is reported in decimal format such that a 60 minute  
observing session would be reported as Teff = 1.00. The column (LM) is  
the average naked eye limiting magnitude seen.  All following columns  
indicate the number of meteors for each shower observed.  For more  
info, see: http://www.namnmeteors.org/guidechap2.html




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.



Dead time: 27 min (break)

Breaks (UT): 4:21-23, 4:30-40, 6:12-19, 7:42-52

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