(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



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




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.



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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