(meteorobs) Observation August 11/12 2012

Sat Oct 6 02:14:19 EDT 2012

The weather forecast for Eastern Ontario was poor for the Perseids peak night, with a large low pressure system moving through.  But it looked like variable skies or broken cloud cover was at least a possibility.  Raymond Dubois joined me for an outing to Bootland Farm, where we setup under a clear-ish sky after sunset.  The clouds soon took over the sky though, just as it was obvious that the Perseids were kicking into high gear.  We casually saw several bright meteors in between clouds.  The sky finally cleared enough after midnight to allow a formal observing session.  Watched and recorded meteors for a little over an hour before thicker clouds moved in from the south.  But a short hour was enough to see some significant rates... 73 meteors (66 Perseids, two Delta Aquariids, one Kappa Cygnid, one antihelion and three sporadics).  The sky during the clear spell was gorgeous (mag 6.5) with a warm temperature, barely any dew and no bugs. 

The brightest Perseid had a magnitude of -3 and left a 3 sec train over a 30 degrees path.  It was also captured by one of my cameras (included in the first composite below).  The persistent train left by this meteor is visible on several of my images.

My two DSLRs captured quite a few Perseids given the short period of clear skies.  Here's three composites assembled from multiple stills:

Canon 7D, ISO 1600, with Tamron 17-50mm lens at f/2.8:
http://tinyurl.com/8jt3wvb

Canon 7D, ISO 800, with Tamron 17-50mm lens at f/2.8:
http://tinyurl.com/9ysr64q

Canon 300D, ISO 1600, with Canon 15mm Fisheye lens at f/2.8:
http://tinyurl.com/9dxexcl

And a few stills... a bright sporadic (possibly SDA) and a fainter Perseid on the left side:
http://tinyurl.com/9f3rgeh

Still pic of a bright Perseid through cloud cover:
http://tinyurl.com/9hhdhk8

Still pic of a Perseid in morning twilight:
http://tinyurl.com/9kr5eqw

Pierre Martin
Ottawa, Ontario

DATE: August 11/12 2012
BEGIN: 04:35 UT (00:35 EDT) END: 5:40 UT (01:40 EDT)
OBSERVER: Pierre Martin (MARPI)
LOCATION: Long: -76 29' West; Lat: 45 23' North
Observing site: Bootland Farm, Ontario, CANADA
RECORDING METHOD: talking clock/tape recorder, cord align.
----------------------------------------------------------

OBSERVED SHOWERS:
Kappa Cygnids (KCG) - 19:00 (285) +51
Antihelions (ANT) - 22:08 (332) -09
Delta Aquariids (SDA) - 23:28 (352) -13
Eta Eridanids (ERI) - 03:00 (045) -10
Perseids (PER) - 03:12 (048) +58
Alpha Triangulids (ATR) - 03:16 (049) +37
SPO (sporadics)
----------------------------------------------------------

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

PERIOD(UT)___FIELD_____Teff___F______LM____SPO_PER_KCG_ANT_SDA_ERI_ATR

04:35-05:40__002 +63___1.08___1.00___6.53___3___66__1___1___2___0___0 = 73

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

MAGNITUDE DISTRIBUTIONS:

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

SPO___0___0___1___0___0___0___1___1___0_____+2.00
PER___1___2___1__10__10__12__10__12___8_____+2.18
SDA___0___0___0___0___0___1___1___0___0_____+2.50
KCG___0___0___1___0___0___0___0___0___0_____-1.00
ANT___0___0___0___0___0___0___0___1___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: None

Breaks (UT): None

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.meteorobs.org/pipermail/meteorobs/attachments/20121006/409fcc80/attachment-0001.html 