(meteorobs) Observation April 21/22 2011
Pierre Martin
pmartin at teksavvy.com
Wed May 25 00:33:40 EDT 2011
Hello all,
Here's my belated Lyrid meteor shower report ;) I was out late at
night for a short one hour session at the Pendleton Airport (about 45
minutes east of Ottawa). I was curious to see what the Lyrids were up
to close to their nominal peak. The 19 days old waning gibbous lurked
some 15-20 degrees in the south-east. To avoid the glare, I had my
chair setup in the long shadow of my car, and I faced the northern
sky, where it appeared darkest. The sky was actually quite
transparent given the moonlight, and I had little trouble seeing fifth
mag stars towards the zenith. There was however just the faintest
hint of Milky Way visible in Cygnus, a far cry from what would be
visible on a dark moonless night. The temperature was unseasonably
cool at just degrees over zero. Given that I was also a bit tired, I
felt rather chilly and underdressed, and I often fumbled with my
charts. But it was great to be out meteor observing again after being
out of action since last December's Geminids.
The minute that I signed on at 3:10am, I was treated to a spectacular
mag 0 sporadic earthgrazer that moved very slowly on a 30 degrees path
in the north, and lasted several seconds. It was a beauty with a
vivid golden-yellow color.
The Lyrids looked quiet until I was surprised by a small "burst" at
3:22am EDT. As many as three Lyrids appeared in the span of just 20
seconds! All of which were faint (mag +4, +3 and +5) and shot in
different directions. A fourth Lyrid (mag +3) was seen just six
minutes later. This had me hoping that the Lyrids would be putting on
a decent performance despite the Moon. However, none were seen in the
following 46 minutes of observing until I quit.
Pierre Martin
Ottawa, Ontario
DATE: April 21/22 2011
BEGIN: 07:10 UT (03:10 EDT) END: 08:14 UT (04:14 EDT)
OBSERVER: Pierre Martin (MARPI)
LOCATION: Long: -75.092 West; Lat: 45.568 North
Observing site: Pendleton Airport, Ontario, CANADA
RECORDING METHOD: talking clock/tape recorder, cord align, plotting
----------------------------------------------------------
OBSERVED SHOWERS:____________________________radiant position
LYR (Lyrids)_________________________________18:13 (273) +32
ANT (Antihelion)_____________________________15:04 (226) -18
SPO (sporadics)
----------------------------------------------------------
OBSERVING PERIODS: 0 = none seen; / = shower not observed
PERIOD(UT)____FIELD_______Teff___LM_____SPO_LYR_ANT
07:10-08:14___15:31 +74___0.98___5.60____3___4___0 = 7
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
------------------------
MAGNITUDE DISTRIBUTIONS:
SHOWER
______0__+1__+2__+3__+4__+5______AVE
LYR___0___0___0___2___1___1_____+3.75
SPO___1___0___0___1___1___0_____+2.33
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 (plotting)
Breaks (UT): None
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