(meteorobs) Observation November 16/17 2009 + images
pmartin at teksavvy.com
Tue Dec 8 23:06:05 EST 2009
Here's my belated report on the Leonid meteor shower:
What a great night!! I had the pleasure of spending the entire night
at Bootland Farm (located west of Ottawa), under crystal clear skies
for the peak night. I was among a lot of company. In fact, it was a
surprisingly well attended night with 9 cars in the observing field,
despite it being a weeknight. Half of those present had telescopes
setup and the other half had come to join me for observing/
photographing the Leonids. Four of us managed to pull an all-nighter,
staying up observing until 6AM! (That was fun!) Overhead, the skies
were excellent with very good transparency and stars down to mag 6.5
at the zenith. Only the last hour had declining limiting magnitude
due to morning twilight. The long night of observing was a pleasure
in that the ground conditions were surprisingly dry for most of the
night, thanks to a very light breeze that kept the air in movement.
It wasn't until nearly the end of the night that we felt a layer of
frost settling down. All in all, a very comfortable night that went
down just below freezing.
Just minutes from my arrival at Bootland Farm, driving along Flat
Rapids Road, I witnessed, at precisely 8:58PM EST a truly amazing
sight... A magnitude -8 slow moving earthgrazing sporadic fireball!!!
The meteor gradually swelled up and took several seconds to travel
along a nearly horizontal line from south-west to west, changing from
blue to orange, before fragmenting spectacularly into several pieces.
I was so taken by this sight that I am surprised I managed to keep my
car under control. This meteor definitely had a relatively shallow
angle and I wouldn't be surprised if meteorite fragments were dropped
somewhere just south of Algonquin Park (based on my rather crude
visual sighting from inside a moving car and from studying an
astrophotographer's lucky image of the same meteor captured about
200km south-west of my location). Unfortunately, my attempt to locate
more images to provide the folks at the University of Western Ontario
a chance to maybe do a more precise analysis on this has not been
fruitful yet. Upon my arrival at Bootland Farm, I was greeted by
excited observers who had all witnessed the amazing meteor!
I took my time setting up my equatorial mount, cameras and
accessories, ensuring that everything worked. I shared my mount with
Ivo's camera, so we were running three Digital SLR's together, all
with wide angle lenses. Although dew was not an issue yet, I opted
not to take any chances, learning from past experience that dew/frost
will almost always appear at some point in the night. Our anti-dew
system was crude but cheap and effective... chemical hand warmers in a
sock, wrapped and taped around the lens. The warmers provides more
than enough heat to keep our lenses dry for several hours.
I signed just after 11pm EST, to start looking for Leonid earthgrazers
with the radiant still hugging the horizon. Perhaps, this was wishful
thinking to bring back memories of the great 2001 Leonids! For the
next hour, I did not catch any earthgrazers but I did see two nice
Leonids of mag 0 with fairly long 30 and 40 degrees path lengths.
After this first hour, I took a break.
I signed "on" again at 1:27am EST. Leonid activity was slowly
increasing. For the next 45 minutes, I caught 10 Leonids, as well as
a good number of sporadics. After that, I took another break to
attend my cameras and grab a snack.
I got back to business at 3:00am EST. For the next hour, the Leonids
were quite pleasantly active with 30 of them seen. No outbursts, but
definitely a mild enhancement of activity. And they were a bit on the
bright side too. During this hour, no less than four negative
magnitude Leonids were seen (all -1's), as well as several mag 0 and
+1's. Almost all of the reasonably bright Leonids left wakes or
persistent trains, and blue-green was a typical color.
The Leonids remained remarkably consistent all the way until dawn.
When I signed "off" at 6am EST, I had bagged exactly 100 Leonids!
What I saw certainly supports the experts' predictions of a plateau of
slightly enhanced rates into the morning hours of the 17th. Although
no fireballs were seen while I was actively observing, I was surprised
at the large number of mag 0 and +1 Leonids that I saw. The average
Leonid magnitude was over a full magnitude brighter than the average
To top it off, the sporadics provided nice consistent rates. The
North Taurids were surprisingly active with some nice average speed
meteors. There was also a definite presence from the Alpha
Monocerotids. All in all, a very productive night! I enjoyed the
quiet night, the good company under dark skies, the Leonids flashing
by and the occasional howls of the coyotes. At the end, I was quite
exhausted and I managed to sleep quite easily in my car until 11am!
When I woke up, I was surprised to see another car still there...
Turns out that Ivo had a long snooze all bundled up in his car too :)
Here's a composite image of all the Leonids captured with Canon 30D
(ISO800) and 18mm lens at f2.8:
And the composite in the Orion region with Canon 300D (ISO800) and
35mm lens at f2.2:
Now I'm keeping fingers and toes crossed for the upcoming Dec 13/14
Geminids!!! With the peak well situated for North America this year,
I am expecting an excellent shower!
DATE: November 16/17 2009
BEGIN: 04:10 UT (23:10 EDT) END: 11:00 UT (06:00 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:_______________________________radiant position
AND (Andromedids)_______________________________01:33 +33
ERI (Omicron Eridanids)_________________________04:02 -02
NTA (North Taurids)_____________________________04:06 +23
STA (South Taurids)_____________________________04:09 +15
NOO (IMO video - November Orionids)_____________05:32 +16
AMO (Alpha Monocerotids)________________________07:28 +02
LEO (Leonids)___________________________________10:09 +23
OBSERVING PERIODS: 0 = none seen; / = shower not observed
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
Notes: 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: 5 min (breaks)
Breaks (UT): 5:20-6:27, 7:13-8:00, 9:27-28, 10:02-06
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