From: TerryMoselaol.com
Date: 19 November 2006 19:25:48 GMT
Subject: LEONIDS - PARTIAL SUCCESS

Hi all,

1. The IAA's Observing Night + Leonid Watch at Delamont Country Park on
Saturday night started well, following a good weather forecast, with
crystal clear skies & very little light pollution. But after an hour or
so we had a bad case of Cirrus Interruptus. Followed by an even worse
case of Stratus Interruptus, which soon became Stratonimbus Interruptus,
i.e. it started to rain. I decided to go home & wait for an improvement
and/or get some sleep and set the alarm for the predicted 04.45 Asher -
McNaught peak. It was still cloudy & raining at 02.00 when I went to
bed. But ever the optimist I set the alarm for 03.45 to allow time to
get up & out to a dark site if it did clear.

But I awoke for a toilet break just before the alarm went off, & I
checked the sky:  pigs do fly! - through a totally clear sky!  I had
left all the observing gear in the car, so I dressed hurriedly & headed
for the nearest dark-sky site, Big Collin, North of Ballyclare in the
Antrim Hills. But as I approached I saw fog on the hill ahead (a common
problem there at this time of year), so I turned & went towards a site
between Belfast & Larne. Again, as I drove to the top of the hill, I
went into fog, so I turned back into the valley & found a deserted lane.
Quickly, out with the lounger, check the watch to start the observing
session: "O5.25" - - - - 05.25!?!? It should have been about 04.15! -
The battery on the alarm clock had chosen that night to fail, and it was
over an hour later than I thought!

So the Asher-McNaught peak had passed.  Oh Deary Me! Or words to that
effect..... Still, the sky was clear, so I observed anyway. And was
rewarded with some good 'normal' or 'Ortho-Leonid' activity for a time
well after the main traditional maximum. I only got 30 minutes clear sky
before more Cirrus Interruptus, but in that time I got six nice Leonids,
a Monoceratid, and a sporadic, plus more later (see below). The Leonids
were spectacular - I had almost forgotten just how fast they are: even
one streaking halfway across the sky takes less than 1/4 second! The
magnitudes were +2, +3, 0, +1, + 1 & -1 with a 1 second train. The
sporadic was mag 0, & the Monoceratid was +1.    The cirrus thickened to
stratus, but I could see a clear patch below it in the West, so I
waited. While waiting I also saw two lovely Leonids through the last
clear area in the sky to the NE (which hadn't been covered yet). One was
a lovely -2 heading down below CrB, with a 2" train. Then one appeared
right down at the NE horizon, ending in not so much a terminal burst as
a terminal flash! It was just like a camera flash going off: I think the
fact that it seemed to be heading almost directly away from me
foreshortened the burst, so it appeared point-like. That was only about
5 degrees above the horizon, and so must have been nearly overhead from
SW Scotland. And if it was -3 for me, at that distance, and at that low
altitude, it must have been a real beauty for anyone there!   I then got
another 10 minutes with a 50% clear sky to the West, from 06.25 -
06.35 but the dawn was encroaching & I ended formal observing. But the
best was yet to come: when driving home in the brightening twilight, I
saw a real Leonid fireball low in the South, with a magnitude of about
-5 ; brighter than Venus!    The sky limiting magnitude was a reasonable
5.7, given that I wasn't that far from Belfast. That's too small a
sample, over too short a period, to calculate a reliable ZHR but it does
show that there's still good activity from the 'normal' Leonids even
after the maximum.

Funnily enough, on the previous evening (17/18), the night of the
'normal' maximum, I only saw two Leonids (+ 1 sporadic) in a 30 minute
break in the clouds from 01.50 to 02.20, with a sky limiting magnitude
of about 5.0.

2. I also got this report (the only other one so far) from IAA President
Pat O'Neill: "Location: Belfast, N. Ireland (urban). 19 November. Time:
0415 to 0515 Atmospheric Conditions: Some thin clouds intervening Total
Leonids: 5, (4 faint, one bright: mag -1) One bright Geminid (mag. -1) *
Three observed within 2 minutes around 0450, coinciding with Armagh
Observatory astronomer David Asher's prediction for increased activity
around 0445. Patrick O'Neill Irish Astronomical Association" [ * Note:
that meteor may have been from Gemini, but that shower does not
officially start until 7 December. T.M.]

DID ANYONE ELSE SEE ANY LEONIDS LAST NIGHT? - If so, please send me a
report.

And roll on the Geminids - the best of the annual showers, in mid
December, with no moonlight this year! More later.....

Clear Skies,

Terry Moseley

Last Revised: 2006 November 20th WWW contact:webmaster@arm.ac.uk

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