(meteorobs) Observation December 13/14 2004
Pierre Martin
dob14.5 at sympatico.ca
Tue Dec 21 00:01:14 EST 2004
Part II of my trip to Virginia...
I woke up late Saturday morning with the ceilling of my tent down to my
face. The wind was so strong that it completely caved-in my tent! To
make matters worse, my air mattress developped a leak. Needless to
say, I had to get out! The day was sunny but cool with constant strong
gusts of wind and I kept battling to keep things from flying away. I
enjoyed some spectacular h-alpha solar viewing with my Coronado PST. A
gigantic prominence full of details was encircling over 1/8 of the
circumference of the Sun, and within minutes I saw it split in two.
What a sight! The rest of the afternoon was spent relaxing and
napping, in anticipation of a long night of meteor observing. Late
into the afternoon, I started getting a little worried as the clouds
seemed to be only thickening and the blue skies were becoming rare.
The radio station I was listening called for ¨partly cloudy¨ night with
a rain shower possible.
Fortunately, the threatening clouds made way for some decent sucker
holes right before 6:30pm EST. The wind died and it was more
comfortable. With the Geminids radiant at the horizon, I setup to face
the North to casually begin hunting for Geminids Earthgrazers.
At 6:32pm EST, the most impressive of a series of spectacular
Earthgrazers appeared!!!!... A vivid mag -1 golden-yellow meteor was
spotted high in the north-east and then moved leasurely across 100
DEGREES path all the way to the western horizon. In my excitement, I
was shouting *really* loudly. It seemed like the Energizer Bunny of
meteors... as it just kept going... going... and... going... It lasted
a good 10-12 seconds until I finally lost sight of it into the western
horizon. Then just 3 seconds later, ANOTHER earthgrazer appeared
seemingly following the same path as the first one... this time, it was
a fainter mag +4 meteor that seemed to ¨skip¨ along the atmosphere
about 6 times until it reached a 40 degrees path! WOW!!!
Over the next half hour or so, under partly cloudy skies, I informally
counted about 10 more impressive earthgrazers. A lot of them flared
in-and-out of visibility continueously as if a rock skipping on a pond.
Some of these long-pathed meteors were also brilliant. At 7:44pm EST,
a spectacular mag -4 Geminid fireball persisted for 20 degrees as it
exploded twice along its path and lit up the surrounding clouds. It
then left behind a 6-7 seconds persistent train that quickly distorted
away.
With the skies now clear enough, I settled into my observing coffin and
signed-on at 8:05pm EST. I faced toward the south, looking about
halfway up. The transparency seemed excellent and the limiting
magnitude approached 6.5. Temperature of about -3C. I took numerous
breaks during the night as I was operating a 35mm camera on tripod.
Between 8:05-9:05pm EST, I recorded a surprising 43 meteors (including
38 Geminids) despite the radiant being still quite low. It was evident
that the rates were probably just passed maximum rates at that time.
At 9:05pm EST, a cloud suddenly materialized above me and forced me to
sign-off (break) from officially counting. The next 20 minutes had
some surprisingly nice meteors seen casually despite the overcast. At
9:25pm EST, the cloud moved away and luckily, the rest of the night
stayed completely clear. The following 5 hours had total (showers
combined) hourly rates as follows: 70, 55, 82, 83 and 69 with the final
half hour of the night having 29 meteors. The Geminids reached their
best rates between midnight and 3am EST. Initially I thought that this
period was a relative lull, but I now believe that this impression was
due to an abundance of faint meteors during that time. For a while, I
was also seeing a great majority of meteors very far away from the
radiant close to the horizons.
On this night, I was joined by a number of the local amateur
astronomers from the Richmond area who arrived after 11pm to enjoy the
Geminids.
Out of the 431 ¨officialy recorded¨ meteors, as many as 11 of them (all
Geminids) were fireball class of mag -3 or better. Many of the
brightest ones were very vividly BLUE! ... They really did looked like
shiny Christmas ornaments darting across, with their leisurely speeds
often allowing a good look before they vanished away.
The brightest meteor of the night was actually seen while I was taking
a short break for a snack. At 1:10am EST, a most magnificent mag -7
Geminid fireball blazed as it lit up the sky and plunged straigth down
into the North. It was one of the most vivid *GREEN* meteors that I
recall seeing in quite some time.
To add variety, the minor shower Monocerotids were surprisingly active
throughout the night, as were the Hydrids and Coma Berenicids near the
end. Sporadics rates were up and down from one period to the next.
At one point during the night, I accidentally hit the mute button on
the new tape recorder I was using. Therefore, I lost 27 minutes of
data before I realized what was happening. It is a good thing I have a
habbit of checking the condition of the tape every now and then,
otherwise I may well have recorded on ¨mute¨ all night.
I kept at it right up till 4:30am EST. By then, I was completely
exhausted but very happy at the results. The Geminids provided quite a
good show even though I was several hours after the predicted peak.
I slipped deep inside my big sleeping bag in my coffin. Before
shutting my eyes, a last glimpse up revealed one more glorious Geminid
fireball... a mag -5 PURE GREEN going down into Canes Minor. Then...
not able to hold my eyelids open any longer I promptly passed out...
I woke up late Tuesday morning, I packed all my stuff, and then took
off for the long trek back home... a very happy camper! :)
Pierre Martin
Ottawa, Ontario
DATE: December 13/14 2004
BEGIN: 0105 UT (2005 EST) END: 0930 UT (0430 EST)
OBSERVER: Pierre Martin (MARPI)
LOCATION: Long: -78.00 West; Lat: 37.54 North Elevation: NA
City & State: Richmond, Virginia, USA
RECORDING METHOD: talking clock / tape recorder / cord align
-----------------------------------------------------------------------
OBSERVED SHOWERS:_________________________________radiant position
XOR (Chi Orionids)_____________________0620 +23
MON (Monocerotids)_____________________0648 +08
GEM (Geminids)_________________________0720 +33
HYD (Sigma Hydrids)____________________0832 +02
COM (Coma Berenicids)__________________1124 +27
SPO (random sporadics)
-----------------------------------------------------------------------
OBSERVING PERIODS: 0 = none seen; / = shower not observed
PERIOD(UT)_FIELD____Teff__LM_____GEM_MON_XOR_HYD_COM_SPO
0105-0205__0245+10__1.00__6.40___38___2___0___0___0___3
0225-0350__0351+13__1.00__6.46___59___3___1___0___0___7
0350-0522__0435+10__1.00__6.48___50___2___1___0___0___2
0522-0642__0535+09__1.00__6.48___69___0___2___0___0___11
0642-0754__0642+06__1.01__6.48___67___2___1___2___3___8
0754-0857__0816+09__1.01__6.48___46___4___2___5___5___7
0857-0930__0918+11__0.55__6.48___25___0___0___2___1___1
TOTALS:_____________6.57_________354__13__7___9___9___39 = 431
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). The next 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
GEM_____1___4___6___7___13__29__36__67__81__59__48__3_____+2.38
MON_____0___0___0___0___0___0___1___3___2___6___1___0_____+3.23
HYD_____0___0___0___0___0___0___0___1___1___3___4___0_____+4.11
COM_____0___0___0___0___0___0___1___1___1___4___2___0_____+3.55
XOR_____0___0___0___0___0___1___0___0___3___1___2___0_____+3.29
SPO_____0___0___0___0___0___0___1___5___7___21__4___1_____+3.64
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. The above
table contains the magnitudes from all observed meteors, and the
average (last column) for showers.
------------------------
SKY OBSCURED (FOV): None
------------------------
Dead time: 91.65 min.
Breaks (UT): 2:05-2:25, 2:30(45sec), 2:34-2:54, 2:56(30sec), 3:07-3:09,
3:20(20sec), 3:30-3:31, 3:40(20sec), 3:42(20sec), 3:53(30sec),
4:07(45sec), 4:23-4:50, 5:01-5:04, 5:19-5:20, 5:25(20sec), 5:34(30sec),
5:42(20sec), 6:02-6:15, 6:24-6:29, 6:36(20sec), 6:40(30sec), 6:42-6:44,
6:46(30sec), 7:06-7:13, 7:45-7:47, 7:56(20sec), 8:22-8:24, 8:54(20sec)
-------------------------
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