(meteorobs) Observation October 20/21 2007 (Bootland Farm)

[Pierre Martin]

Here's my full report from last night's extraordinary Orionid shower!

I left home at 10:30pm EDT under 99% overcast skies.  On my way  
there, the skies gradually cleared.  As I was driving along Hwy 17  
and listening to my ipod, a beautiful pink mag zero Orionid  
earthgrazer surprised me!  It appeared from the top of my windshield  
and down into the western sky!  When I arrived at Arnprior, I was  
greeted by completely clear skies.  You got to love this hobby!  :0)

While setting up my cameras at Bootland Farm, I happened to glance up  
and saw a memorable meteor... A very nice -1 mag Taurid across a long  
path to the south.  It left a beautiful wake behind it.  Raymond  
Dubois setup his mount and camera next to me to do meteor photography  
while he casually observed the shower.
The night was unseasonably mild for this time of the year with a low  
of +8C.  I came prepared with my winter sleeping bag, and parka, but  
found that I was actually too warm and didn't need either!  A nice  
breeze blew for most of the night, keeping dew from forming until  
later on at night.  It was a real treat to observe with such a  
comfortable night.  The sky quality was about average transparency  
(3/5) until 3:30am.  At that time, clouds suddenly moved in and  
forced me to take a break from formal counting until it cleared up  
again half an hour later.  Luckily, the clouds moved quickly and our  
patience was rewarded... After the clouds parted, the transparency  
was above-average (4/5) quality and the limiting magnitude up to  
6.45 !  The winter constellations were stunning.  We could both see a  
part of the faint zodiacal band across the ecliptic.  The skies  
stayed clear until a second "wave" of cloudiness arrived at 5:15am  
EDT, forcing sign off for good.

The result was 3 effective hours (TEFF) of formal meteor observing.   
In that time, I recorded a whopping 184 meteors!!  This breaks down  
into 133 Orionids, 11 Taurids, 6 Epsilon Geminids, 5 Leo Minorids and  
29 sporadics.

The Orionids (ORI) were clearly showing a state of outburst last  
night.  The first period (70 minutes TEFF) had 30 ORI with the  
radiant still quite low.  My second period (exactly 60 minutes TEFF)  
exploded with 52 ORI!!!  My third period (just 46 minutes TEFF - cut  
short due to cloudiness) was even busier with 51 ORI!  Those are the  
highest ORI rates that I've ever seen.  Most of the late night  
Orionids were evenly spaced with a meteor coming at a rate of one per  
minute or better.  But there was a few impressive bursts.  The best  
was at 4:16am EDT when 7 meteors (6 ORI and 1 SPO) all appeared  
within 10 seconds!  A couple of these were even simultaneous!  Now  
that was exciting!!  :0))
There was a good crop of bright ORI, with 11 of them having negative  
magnitude meteors (the brightest being a FABULOUS mag -5 fireball  
that shot down from high up in the southern sky - right in the middle  
of my field of view!  It lit up the surrounding sky and swelled up  
into a gradual flaring along it's path.  It then left behind a  
brightly colored persistent train lasting 4 minutes!  One of my  
cameras even manage to catch it, along with the expanding and  
twisting train).
In general, the ORI were fairly bright with a total average limiting  
magnitude of +2.5.  (In comparison, the sporadic background was more  
than a full magnitude fainter than the ORI).  Some of the brighter  
Orionids were vividly colored blue or green.

When the sky clouded over at 5:15am EDT, I signed-off from formal  
recording but I continued to look up in the small holes - as well as  
attending my cameras.  A number of additional Orionids appeared  
(including a fireball behind clouds), but I had the impression of  
somewhat lower rates by then.  Feeling quite exhausted, and with  
morning dawn on the way, I wrapped myself up in my sleeping bag and  
fell asleep like a bug.

A night I won't soon forget!  My cameras captured a number of nice  
ORI too ... more on this later after I get a chance to go through all  
the frames.

Pierre Martin
Ottawa, Ontario


DATE: October 20/21 2007
BEGIN: 0525 UT (0125 EDT) END: 0915 UT (0515 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
NTA (North Taurids)_______________________________02:36 +18
STA (South Taurids)_______________________________02:40 +12
TAU (Taurids - above radiants combined)
ORI (Orionids)____________________________________06:20 +16
EGE (Epsilon Geminids)____________________________07:00 +27
LMI (Leo Minorids)________________________________10:56 +37
SPO (sporadics)
----------------------------------------------------------

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

PERIOD(UT)___FIELD____Teff____F______LM___SPO_ORI_EGE_NTA_STA_TAU_LMI

0525-0638___0429+19___1.22___1.00___6.30____7__30___4___2___0___1___0
0654-0827___0537+11___1.00___1.01___6.44____8__52___1___4___1___1___4
0827-0915___0634+14___0.77___1.00___6.45___14__51___1___0___2___0___1

TOTALS:_______________2.99_________________29__133__6___6___3___2___5  = 
  184

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
______-5__-4__-3__-2__-1___0__+1__+2__+3__+4__+5__+6______AVE

ORI____1___0___2___2___6___7__12__28__29__30__12___4_____+2.54
SPO____0___0___0___0___1___0___0___1___4__17___6___0_____+3.83
EGE____0___0___0___0___0___0___0___0___3___3___0___0_____+3.50
NTA____0___0___0___0___0___0___0___0___2___2___1___1_____+4.17
LMI____0___0___0___0___1___0___0___1___0___3___0___0_____+2.60
STA____0___0___0___0___0___0___0___0___1___2___0___0_____+3.67
TAU____0___0___0___0___0___0___0___0___1___1___0___0_____+3.50

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):  yes - a few clouds

10% clouds from 7:26-7:33

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

Dead time: 35 min (breaks)

Breaks (UT): 6:38-54, 7:01-26, 7:34-35, 8:09-16, 9:00-02