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(meteorobs) Observation November 17/18 2001
Here is my (late) verbal report...
For this year's Leonids shower, I had the pleasure to travel with
another local observer, Michael Vasseur. We were both determined to
drive as far as was necessary (from Ottawa, Ontario) to an area that
would have the best chances for clear skies. We originally hoped to
setup at Manitoulin Island, but we soon realized that we had to
travel much further if we wanted to maximize our chances for perfect
weather...
We spent the entire day on Friday Nov 16 driving from Ottawa to
Cambridge (Ohio). We debated whether it would be a good idea to try
and find a dark site to start watching for Leonids on the pre-max
night. We finally decided against it as we were already tired from
being on the road all day and the sky had cirrus clouds and poor
transparency. Instead, we were very anxious to find an internet
connection to check weather updates for the peak night. We found a
library which graciously let us use their computers for a few
minutes. An updated CMC weather map showed Ohio to be in a risk area
with thin clouds or fog predicted for the big night. With this in
mind, we drove south another few hours until we arrived in
Parkersburg (West Virginia) by late evening. We finally stopped at a
motel for a well deserved good night's sleep.
The next morning, we woke up with one of the thickest fog I've ever
seen. The sky was supposed to be clear but the fog was thick enough
to block the Sun and visibility was severely affected. Uploading
weather updates on Michael's laptop computer showed the bad news; fog
and humidity for the peak night. We also noticed the low pressure
over Texas was starting to spread north-east. After examining our
road atlas, we quickly chose a few candidate observing sites. The
first possibility was North Bend State Park only about 20 minutes
away from our motel. A quick visit at this site was worth it as we
found a very nice open field where we could setup, and staff there
was very helpful. On the other hand we were concerned that we were
too low in elevation, and might get caught in fog. A quick phone call
to Wayne Hally in New Jersey confirmed our suspicions that the fog
might be a problem, and he suggested we try to get as high in
elevation as we could! (Thanks for the tip Wayne ;-)
We got the show on the road and travelled south-east all afternoon
until we reached the National Radio Astronomy Observatory in the
Appalachians. We were hoping that a group would be there to greet us
or that we'd at least get permission to setup there. Upon arriving
near the impressive radio dish, we were disappointed by what we saw.
The entire parking lot was full of light fixtures that would no doubt
cause interference. The location is also in a valley in between the
mountains and we feared that fog might be bad there. By chance, we
met an individual who was arriving to start his shift, and was
helpful in suggesting a few sites that would offer much darker skies.
As the Sun was getting low, we didn't waste any time so we hit the
road again.
We knew that the nearby Spruce Knob (in Monongahela National Forest)
was the highest elevated point in West Virginia, and so we headed
that way. Soon, our GPS indicated we had reached over 4000 feet of
altitude. As the Sun was just about to hit the horizon, we were
getting nervous that the dense forest would obstruct our view of the
sky if we didn't find a spot to setup real soon before it got too
dark. Finally, after a few minutes of exploring a small dirt road
going up the mountain, we came up to a flat wide open area with a
surprising lack of trees. It provided a very decent view of most of
the sky, including excellent southern horizons. We looked at each
other and said... "Wow! This is our spot!!!". We began setting up in
the middle of the field. Unpacking our telescopes and my meteor
observing coffin was slightly time consuming due to the uneven ground
and branches from dead trees lying all over the place. We were also
setting up gear well after sunset, so it was a bit difficult to move
around. We kept busy most of the evening making sure our telescopes
(Meade ETX-90 and Celestron C8) were properly polar aligned and ready
to run piggyback astrophotography. We wrapped our camera lenses with
heater pads to prevent dew from causing problems. Below us in the
valleys, we could already see the dreaded blanket of fog! Thank God
we were at a high elevation! Overhead, the Milky Way in Cygnus was a
stunning sight to say the least. I could also see the Gegenshein
fairly easily along the ecliptic.
I signed on at 10:30pm local time. The LEO radiant was still about an
hour away from rising, but I simply lied back to enjoy the dark
skies. I plotted for some of the minor showers active at that time.
Once Michael finished setting up his camera and scope, he also lied
down to enjoy the gorgeous sky and then went for a short nap. The sky
slowly improved as the fog gradually dissipated below us and the
worse of the dew had fallen. The air was still and the area was
extremely quiet. It was as if we were the only ones under the awesome
night sky; a very peaceful experience. Every once in a while, I
logged a sporadic meteor on my chart and recorded my observations. I
tried to keep my voice down as I knew Michael was fast asleep trying
to recharge his batteries after spending the entire afternoon driving.
At exactly 11:43pm, the peace was suddenly shattered as I began
screaming at the first Leonid earthgrazer climbing straight up from
the east!!! With the Leonid radiant only 1 or 2 degrees above the
horizon, this most impressive meteor rose from the tree-line and shot
right past the zenith at a bright magnitude -3. Appearing like a
rocket, it travelled a length of over 50 degrees. It had vivid
colors, changing from yellow to blue and flared twice on its path.
Michael woke-up in a jolt due to my screaming, and immediately
attended the cameras to begin guided time exposures.
As if somebody had flicked a switch, impressive Leonids earthgrazers
started appearing on average every 5 minutes. One of them split the
sky in two with an 80 degrees long path and it flared to magnitude
-3. Another grazer produced a colorful burst of magnitude -4 in the
south-west. A particularly memorable sight came at 1:16 local time
when a pair of 50 degrees long Leonids followed within seconds of
each-other in the same area in the sky, while a third mag -1 beauty
appeared only a minute later. All these meteors skimming the upper
atmosphere were quite awesome!!! After this initial excitement, I
took a 12 minutes break at 12:45am to rest my voice from yelling so
much. Besides, I was also very hungry and I needed a piece of sugar
frosted chocolate cake.
At around 1am local time, the radiant was still low in the east, but
the Leonids were surprisingly active. I was already seeing an average
of more than one Leonid every minute. Lots of long paths and bright
colorful meteors.
By 2am, rates were increasing steadily. I was now averaging two
Leonids every minute, although there were some periods with bursts of
a few Leonids within seconds. Beautiful Leonid fireballs of magnitude
-4 appeared at 1:33am and 1:45am. Both left persistent trains visible
for up to one minute. Many other meteors were mostly colored yellow.
Just as we hit 3am, the Leonids rates had jumped to an average of 4
every minute. There were a number of near-simultaneous Leonids. One
burst of meteors included four Leonids that all shot by within a mere
two seconds. Bright meteors were still plentiful with several in the
negative magnitudes. One Leonid was a "point" meteor appearing
directly on the radiant. It did not have any motion at all except for
a tiny drifting train. At the bottom of the hour, the meteors kept
coming faster and faster. The intensifying rates may also have been
all the more dramatic thanks to the improving sky transparency
allowing 7th magnitude stars to be seen fairly easily. During one
occasion, I watched a nice Leonid going down into the south-east
horizon. At the same time, I saw a brief flash lighting up the sky.
Then, Michael told me to turn around and face the western sky. Right
there near the horizon was a thick meteor train from an exploded
fireball that lingered there for at least *several* minutes!!
At 3:52am, I jumped and screamed (nearly losing my voice) as a burst
of 10 Leonids all appeared fairly close together in the south within
just 15 seconds.
At 4am, Leonids average rates were now falling at 10 meteors per
minute. Keeping track of magnitudes was starting to become
challenging as I spoke quickly in my tape recorder while more Leonids
would shoot overhead. My tape recorder was now running continuously
to help record the action. There appeared to be a more even mix of
both bright and faint meteors. Almost every bright Leonids that
streaked overhead left a train behind, usually lasting a few seconds.
At 4:30am, I abandoned all hopes of trying to record individual
meteor magnitudes. The Leonids were coming fast enough at this point
that I felt I couldn't keep up accurately enough. Instead, I started
to say "BEEP!" in my tape recorder every time I saw one. Between all
our yelling and my talking clock working like crazy, I'm sure we made
quite a racket! At 4:45am, a fantastic mag -10 fireball exploded with
a flash near the horizon and left behind a thick train persisting for
a few minutes. Too bad I didn't see that one all that well since it
was some distance away from the center of my field of view.
My best rates were seen shortly before morning twilight began to
interfere. Despite the annoyingly bright glare cast by the cone of
the zodiacal light in my field of view, the Leonids were roaring!
Between 5:10am and 5:40am, I was recording an average of 40 meteors
per minute!!! They were all over the sky. During the most active 30
minute period alone, I took note of at least four major fireballs
ranging in brightness from magnitude -7 to -10 ..dot simply
stunning!!!!!!
Under brightening morning twilight, it became apparent that the peak
seemed to occur slightly later than predicted. As the sky got
brighter, scores of Leonids were still shooting furiously no matter
where I stared in the sky.
At 6:05am, I finally "signed-off" as my limiting magnitude had
dropped below 5.0. At this point, I put the tape recorder and clock
aside, and simply lied back to keep watching casually for another 25
minutes. I was very impressed by the amount of bright Leonids that
kept coming in such a bright sky. I'm not sure why, but the Leonids
seen at this moment had truly gorgeous vivid colors! Most were green
and blue, but the most amazing was the one that appeared pure
*RED*!!! I don't think I've ever seen one like that before. Perhaps
the brightening sky was reducing glare on the brighter meteors and
that might have contributed to enhance the colors.
At 6:30am, I was pooped out and my vocal cords were hurting. I don't
even remember falling asleep in my coffin all covered in my tarps,
but the hot morning Sun sure didn't fail to wake me up. Here I was
still in winter clothing and the temperature was already at least
15C! As I woke up, a pick-up truck happened to drive by and the
person told us that the nearby 4900 feet high "Sky Deck" (offering a
360 degrees view of the mountains) was apparently jam-packed as of
4am. I'm actually glad we had this nice quiet spot away from the
crowd, as it was perfect for all the gear we had.
Good old Murphy definitely *did* pay us a visit at the worse possible
time. At 4:57am, my tape recorder reached the end of the tape but
failed to do an auto-shut. At one point, I just happened to remember
that it would be good to check if the tape was still running okay. To
my unpleasant surprise, the tape was not turning. I was not
impressed, and I began to wonder how much data I had lost already.
Turns out I lost only a mere 45 seconds between the time my tape
stopped rolling and my inspection of it....whew!!!! Talk about a
close call. Had I forgotten to inspect the tape, I may very well have
had zero data for the best part of the Leonids. The astrophotography
also had a few problems. The mount holding one of the cameras for
piggyback photos had broken apart and the camera fell to the ground.
The other camera mounted on my scope doing piggyback photos had a
mis-loaded film for the last 2 hours before dawn - that film is
completely blank. Fortunately, Michael quickly managed to setup one
camera on a small tripod, and got some decent unguided photos near
the peak time. One photograph taken beside the radiant shows as many
as 18 Leonids!
For me, this was the finest meteor shower I've ever seen. The
combination of bright earthgrazing meteors, near storm-level rates
and exceptionally dark skies was an unforgettable experience. Thanks
to the excellent sky transparency, I recorded a grand total of 3504
meteors - that's even more compared to the 1999 storm I saw in Spain.
I certainly don't regret the 22 hours drive it took to observe this
year's Leonids! Awe-inspiring... to say the least.
Standard meteor report form follows below, with data included for
both Leonids and minor showers active that night. There were good
Taurids by the way - that is until I gave up on them when Leonids got
me really busy...
Pierre Martin
Ottawa, Ontario
DATE: November 17/18 2001
BEGIN: 3:25 UT (22:25 EST) END: 11:05 UT (06:05 EST)
OBSERVER: Pierre Martin (MARPI)
LOCATION: Long: -79 35' West; Lat: 38 42' North Elevation: 4180 feet
City & Province: Spruce Knob (Monongahela Nat'L Forest) West Virginia, U.S.A.
RECORDING METHOD: talking clock/tape recorder
-----------------------------------------------------------------------
OBSERVED SHOWERS: 3-letter code; radiant position
LEO (Leonids) 10h12 +22
TAU (North and South Taurids) 04h44 +22
AMO (Alpha Monocerotids) 07h36 +01
DER (Delta Eridanids) 03h56 -01
IAU (possible Iota Aurigids) 05h00 +37
SPO (sporadics) -
-----------------------------------------------------------------------
OBSERVING PERIODS: 0 = none seen; / = shower not observed
PERIOD(UT) FIELD Teff F LM SPO LEO TAU AMO DER IAU
03:25-04:27 04h19 +15 1.00 1.00 6.63 6 0 2 1 0 0
04:27-05:25 05h09 +15 0.96 1.00 6.63 8 12 0 1 0 0
05:37-06:38 06h12 +14 1.00 1.00 6.79 7 45 5 0 0 0
06:38-07:38 07h18 +16 1.00 1.00 6.95 17 91 6 2 0 0
07:38-08:38 08h16 +09 1.00 1.00 6.95 13 205 / / / /
08:38-09:39 09h32 +11 1.00 1.00 7.02 12 652 / 1 / /
09:39-10:40 10h16 +13 1.00 1.00 7.08 9 1836 / / / /
10:40-11:05 11h02 +20 0.42 1.00 5.97 2 571 / / / /
-----------------------------------------------------------------------------
TOTALS: 7.38 74 3412 13 5 0 0 = 3504
-----------------------------------------------------------------------------
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 I did not
spent looking at the sky). One hour = 1.00 teff. The fourth column
(LM) is the average naked eye limitimg magnitude, determined by
triangle star counts. All following columns indicate the number of
meteors for each shower observed.
MAGNITUDE DISTRIBUTIONS:
SHOWER -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 +1 +2 +3 +4
+5 +6 AVERAGE
SPO 0 0 0 0 0 0 0 0 0 0 3 3 10 5 15
25 3 +3.19
LEO 3 0 3 2 3 3 8 20 21 47 78 87 215 195 199
106 4 +2.18
TAU 0 0 0 0 0 0 0 0 0 0 0 2 1 0 4
5 1 +3.92
AMO 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2
2 0 +4.20
--------------------------------------------------------------------------
TOTALS: 3 0 3 2 3 3 8 20 21 47 81 92 226 201 220 137 8
--------------------------------------------------------------------------
Note: Magnitude scale is to determine the brightness of sky objects.
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.meteors, and the average for showers.
SKY OBSCURED:
None
------------------------
Dead time: 17 minutes (2.25 min for plots)
Breaks UT: 5:18 (10 sec), 5:25-5:37, 6:32 (45 sec), 8:49 (45 sec),
9:57 (60 sec)
------------------------
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