(meteorobs) Observation April 22/23 2007
Pierre Martin
dob14.5 at sympatico.ca
Fri Apr 27 18:45:10 EDT 2007
Hello all,
This past Monday morning, I woke up and drove to Bootland Farm (west
of Ottawa) to observe post-maximum Lyrids. When I arrived there at
2:00am EDT, I was greeted by Sanjeev who was out observing with his
85mm refractor. The Moon was just setting and the skies were
improving. The slight haze that I had noticed earlier in the night
was also dissipating. It was nice to be out at a dark sky site
again! The Spring Peepers were out in full force, and every now and
then I could hear the sound of Ruffed Grouse doing their "drum
beat". The temperature was nice, and dry. Overhead, the Milky Way
and summer stars were rising. What a nice way to start the week!
Sanjeev treated me to a nice view of several galaxies all visible at
once from the Virgo cluster. I'm always impressed at how much a good
quality small scope can see under dark skies.
I settled for a two hour meteor watch. I was pleasantly surprised at
the overall rates... 39 meteors! The Lyrids were productive with 20
seen, even though the predicted maximum was already passed by several
hours. I had one instance of a pair of Lyrids appearing less than 3
seconds apart within about 20 degrees of each other. Although no
fireballs were seen, meteor brightness was fairly high. The
brightest Lyrid was an almost pure-white mag -2 beauty that shot 20
degrees low in the south-west before I lost sight of it behind my
car. The next nicest Lyrid was a mag -1 meteor that travelled 20
degrees toward the north and left a sharp 2 sec train. Other bright
Lyrids were typically colored either white or blue.
Sporadics rates were quite good too. The best was a mag -1 yellow/
orange earthgrazer at 2:46am EDT that shot very swiftly 30 degrees
path across northern Ophiuchus, and left a 3 sec train.
By 3:00am, the skies were impressive. The LM peaked at 6.5, and I
could see lots of structure in the Milky Way right down to
Sagittarius! Even the faint bulge of the Milky Way in southern
Ophiuchus was starting to show some faint dark lane structures.
At 4:35am EDT, I signed-off just as the sky was beginning to brighten
with dawn. I wrapped myself deep into my sleeping bag and promptly
fell asleep. At 7:45am, my trusty talking alarm clock woke me up...
and it was time to pack my stuff and head off to work. Bootland Farm
is a wonderful site... remote enough for decently dark skies..... but
still close enough to make short week-night or pre-dawn sessions
possible!
Clear skies,
Pierre Martin
Ottawa, Ontario
DATE: April 22/23 2007
BEGIN: 0620 UT (0220 EDT) END: 0835 UT (0435 EST)
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, plotting & cord align
----------------------------------------------------------
OBSERVED SHOWERS:_______________________________radiant position
ANT (Antihelions)__________________________14:56 -16
LYR (Lyrids)_______________________________18:04 +34
ETA (Eta Aquarids)_________________________21:36 -07
SPO (sporadics)
----------------------------------------------------------
OBSERVING PERIODS: 0 = none seen; / = shower not observed
PERIOD(UT)___FIELD____Teff____F______LM____LYR__SPO__ANT__ETA
0620-0721___1706+22___1.00___1.00___6.43___11___10____1____0
0721-0835___1806+22___1.15___1.00___6.37____9____8____0____0
TOTALS:_______________2.15_________________20___18____1____0 = 39
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
______-2__-1___0__+1__+2__+3__+4__+5______AVE
LYR____1___1___2___2___5___2___5___2_____+2.25
SPO____0___2___1___1___3___7___1___3_____+2.50
ANT____0___0___1___0___0___0___0___0_____+0.00
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. The above table contains the magnitudes from all observed
meteors, and the average (last column) for showers.
------------------------
SKY OBSCURED (FOV) (UT): None
------------------------
Dead time: 6 min (incl breaks and plots)
Breaks (UT): 7:38-43
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