(meteorobs) Observation May 5/6 2011
Pierre Martin
pmartin at teksavvy.com
Tue May 24 23:42:50 EDT 2011
Hello all,
On Thursday May 5, I took advantage of the clearing skies to do a full
night of meteor observing at Bootland Farm. And since clear skies
have been rather scarce this Spring, I didn't want to miss a chance to
catch some Eta Aquarids in the morning sky. I had a fair amount of
company with 5 other guys out with scopes and cameras, some of which
were out for most of the night until morning dawn.
The weather forecast was very accurate this time, with the clearing
happening in the west-end as scheduled, followed by very clear air for
most of the night. Indeed, the transparency at was a wonderful 4/5
all night long. The sky at Bootland Farm was right up there with some
of the best nights I've seen at this site, with mag 6.5 stars and a
well structured rising summer Milky Way. The gorgeous sky was
enhanced by a chorus of wildlife sounds... Spring peepers, owls,
ducks, coyotes and deer were heard relentlessly. What a glorious
night! With a nice breeze keeping things dry, mild temperature and no
bugs, it was hard to wish for any better. And it was great to be back
at Bootland Farm; probably my favorite observing site.
I decided to spend the entire night looking for meteors. I signed on
at 11:00pm, facing the south-east sky, and I went on until dawn for a
total of five hours effective time, taking the odd break to stretch my
legs and catch a few glimpses in Joe's 12.5" dob.
The first hour (11pm-12:06am EDT) was dreadfully slow with just two
meteors, but that was not unexpected due to the early start time and
the lack of visible shower radiants. One of the two sporadic meteors
seen was an impressive 60 degrees long mag +3 earthgrazer though.
Things were not much better during the second hour (12:06-5:07am).
But the third hour (1:07-2:11am) was a bit better with three sporadics
and three antihelions.
The fourth hour (2:11-3:29am) saw a significant increase in sporadic
rates, with as many as 8 seen, as well as 3 antihelions. The most
impressive meteor in this period was a vividly colored blue-green mag
0 antihelion in eastern Ophiuchus.
The Eta Aquarids (ETA) suddenly woke up in the fifth hour
(3:29-4:35am). As many as twelve ETA's were seen in the final 45
minutes of viewing, just as the sky was brightening in twilight. Many
of them had the "classic" Eta Aquarid look to them, shooting like
bullets across impressively long paths. The best moment came just
before 4am EDT when a number of ETA's were caught in a short span of
time. At 3:54am, a gorgeous mag 0 orange to blue ETA was seen
shooting in the east, leaving behind a 1 sec train. Barely 10 seconds
later, a fainter ETA shot very swiftly across the zenith! This was
followed two minutes later by a pair of ETA's appearing in the same
general sky area just 10 seconds apart! The ETA's then continued at a
fairly regular pace until morning twilight forced me to quit. This
last hour's pleasant total of 21 meteors made up for the low rates
seen earlier in the night.
I was pleased at the ETA's performance given the low radiant position
at 45 degrees latitude. These are the highest rates I remember seeing
from this shower in years.
Pierre Martin
Ottawa, Ontario
DATE: May 5/6 2011
BEGIN: 03:00 UT (23:00 EDT) END: 08:35 UT (04:35 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, plotting
----------------------------------------------------------
OBSERVED SHOWERS:_______________________________radiant position
ETA (Eta Aquarids)______________________________22:40 (340) -00
ELY (Eta Lyrids)________________________________19:22 (291) +43
ANT (Antihelion)________________________________16:00 (240) -21
SPO (sporadics)
----------------------------------------------------------
OBSERVING PERIODS: 0 = none seen; / = shower not observed
PERIOD(UT)___FIELD______Teff___LM____SPO_ETA_ANT_ELY
03:00-04:06__15:26+15___1.01___6.50___2___/___0___0
04:06-05:07__16:27+15___1.00___6.53___3___/___0___0
05:07-06:11__17:25+15___1.00___6.55___3___/___3___0
06:11-07:29__18:26+14___1.01___6.50___8___/___3___0
07:29-08:35__19:26+19___1.10___6.06___7__12___2___0
TOTALS:_________________5.12_________23__12___8___0 = 43
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
SPO___2___2___5___6___7___1_____+2.74
ETA___3___0___0___5___1___3_____+2.83
ANT___1___1___0___3___3___0_____+2.75
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
(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: 20.5 min (breaks) + 7.15 min (plotting) = 27.65 min
Breaks (UT): 3:27-31, 4:05 (30 sec), 5:48-50, 6:34-48
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