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(meteorobs) Possible Geminid lunar flashes need confirmation

Return-Path: <cudnik@cps.pvsci.pvamudot edu>
Date: Wed, 15 Dec 1999 13:59:12 -0600
From: cudnik@cps.pvsci.pvamudot edu
To: SteveH8835@aol.com, dunham@erols.com
Subject: Re: Lunar Geminids
Cc: cudnik@cps.pvsci.pvamudot edu
Content-MD5: tzMaLWbJufC4mQ0lZW3eeQ==

Hi-
I systematically monitored the Moon visually over the previous two evenings
for 
flashes from meteoritic impacts.  I saw several suspects, but none had the
100% 
confidence level that my lone Leonid observation had.  I will summarize 
separately for each night...
 
14 December 1999

SAO 164844 disappeared at 1:18:10.5, not corrected for reaction time.
A 10-11th magnitude star, whose ID I do not know (could you foreward me
this or 
let me know where I can find it...) disappeared at 1:53:29.3.

One of my sessions was between 2:26 and 3:07UT, and I did not record seeing 
anything definite except a possible 4th mag. event about 2 arcmin from the 
terminator near the center of the Moon's disk.  I was not looking directly
at it 
when I observed it, I give it a 70% confidence that I saw something.

An unidentified (by me...) star vanished behind the Moon's limb at 2:35:15.4; 
another "anonymous" 8th magnitude star was occulted at 3:04:51.9.

15 December 1999

I thought I saw six faint impacts between 0:55 and 0:56UT at the limit of 
visibility near the center of the Moon's disk.  One slow one was seen just
south 
of the lunar equator about 1 arcmin from the terminator at 1:07:56 (7th to
8th 
magnitude).

After a dust storm came thru (I was protected by the walls of the roll-off 
observatory I was in...) at 1:53UT, leaving the sky rather dusty for the next 
hour or so...I saw the following four potential events:

	2:12:29, confidence 30 to 50%, mag. 6-7
	2:14:51, confidence 30 to 50%, mag. 6-7
	2:16:57, confidence 30 to 50%, mag. 6-7
	2:20:13, confidence 60 to 70%, mag. 4-5
	
I also saw two further events, each about 6th magnitude:

	3:05:01, 6th mag, 60-70% confident, about 5' from lunar limb at limb
	 angle ~30 deg. N
	3:09:40, 6th mag, my surest observation of the night at 75% confidence,
	 lasted about 1/2 second (as did many of the others...), about 10' E of 
	 the terminator very near the lunar equator (5' E of lunar disk center).
	 
I estimate seeing/suspecting about a dozen or so additional events that I am 
very unsure of (confidence level 10 to 20%) over the course of this evening, 
each at or near the limit of visibility or otherwise faint.  I noticed the
vast 
majority of my suspected sightings were clustered around the center of the
lunar 
disk, and many were much longer in duration (1/2 to 3/4 sec.) than the Leonid 
impacts.

The single occultation event of the evening for my site was an "unnamed" 8th 
magnitude blue star, at 3:27:39.5+/-0.5, with a 0.1 second step, probably a
very 
close double with roughly equal components.
____________________________________________________________________________
____
Several of the suspects reported here, as well as those reported by Steve 
Hendrix, are bright enought to be seen with a low-light video camera.  We
hope 
someone has video of the lunar darkside around these times to confirm/deny
the 
events.  In each case above, the observation was made with a 14-inch f/11 
Schmidt-Cassegraine at ~110 power under very clear skies (except the dust 
episodes mentioned above...). Saw many Geminids, including a count of 56 in
one 
half hour period on 14 Dec. UT.

	Brian Cudnik


Joan and David Dunham
7006 Megan Lane
Greenbelt, MD 20770
(301) 474-4722
dunham@erols.com
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