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From: TerryMosel@aol.com
Date: Mon, 11 Aug 2003 19:07:20 EDT
Subject: Enhanced Perseids?, Lecture in Armagh

Hi all,

1. Those who attended the 'Moseley Perseid BBQ' last night were blessed with 
a beautifully clear sky, a magnitude -7 Iridium Flare, & quite nice views of 
Mars later, but not too many Perseids, thanks to the almost full moon. Alan 
Fitzsimmons was there with his nice 8-inch SCT for some proper eyeball observing, 
as a change from watching the monitors on the Isaac Newton Telescope, William 
Herschel Telescope, New Technology Telescope etc! His wife Ann saw twice as 
many Perseids as I did, and I'll not embarrass either of us by saying how many!
   Anyway Alan mentioned that he had seen something on the 'Net about 
possible enhanced Perseid activity on August 13.0, and promised to send it to me, 
which he has done with the caveats in the introduction; below. Talking about it 
last night, he confirmed that if there is any activity from this filament, they 
are likely to be large particles rather than small, as the latter will all 
have dispersed by now. That means that IF there's any enhanced activity, the 
meteors may be bright enough to be seen in spite of the moonlight:

"Dear Terry, Below is the message that I saw on an internet discussion board. 
Although it's potentially interesting, there's a number of reasons to be 
wary.
 1. This came not from Esko Lyytinen himself, but from someone else, so there 
are possibilities of mis-communication.
2. The orbit of Swift-Tuttle is considerably more uncertain than with
Temple-Tuttle, due to its larger period and large non-gravitational forces.
3. The Leonid predictions by David [Asher] and Rob [McNaught] were based on 
matching their models with previous Leonid stream observations, it is not 
obvious whether this is the case in this instance.
  So to re-iterate, be wary!"
Alan"

************************************************************************
"Hello you all,
You surely all know that Perseid meteor stream is already active, with a 
maximum predicted on August 13th, ~4:40 UT (cf www.imo.net)
   But recently Esko Lyytinen (Finland) has computed the evolution of a 
stream ejected in 569 AD, and found an intersection with the Earth on August 13, 
~0:00 UT.
   I did the same, but the orbit I have is different from that of Esko. His 
is taken from Yau et al 1994 (MNRAS) and Nakano ; mine is from a colleague on 
holidays now, so I cannot say exactly where the difference does come from.
   Anyway, my result does not give the encounter on Aug. 13th.
  SO WATCHING ON PERSEIDS WILL BE A UNIQUE OCCASION TO TEST THE ORBIT OF THE 
COMET ON SUCH A LONG TIME PERIOD !!!
   Please, see www.imo.net to kow how to fill a report and where to send it 
;-)
And most of all, clear skies ! Jeremie"
   So, it  might be worth a special look, but don't be too hopeful!

2. I got the following message to pass on from Eamon Rafferty at Armagh 
Planetarium: 
   "If any of you are interested in attending the two ESA  lectures in the 
Market Place Theatre, Armagh on Tuesday 19 August at 7.30pm. let me know 
a.s.a.p. There are still some places left. Details:   Professor David Southwood, 
Director of Science at the European Space Agency, will give the first lecture 
entitled "Europe in Space",  and Dr Mark Doherty, Head of Earth Observations at 
the ESA will give the second: "Observing the Earth from Europe"."

Many thanks, Eamon: Armagh Planetarium eamon@armaghplanet.com, tel 028 (048 
from ROI) 3752 4725

Clear Skies,

Terry Moseley

Last Revised: 2003 August 12th
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