(meteorobs) Meteor Activity Outlook for November 17-23, 2012

[Skywayinc at aol.com]

In a message dated 11/16/2012 9:48:11 P.M. Eastern Standard Time, Bob  
Lunsford wrote:
 
The timing (for possible Leonid activity on Tuesday morning) is a bit  
early for observers in North America. At a ZHR of 10-15, the eastern portion of  
North America may see a small fraction of these if they show up at all. 
Lastly,  the IMO calendar states that particles from the AD 1400 would produce 
meteors of  below -average brightness. It does not sound like anything 
exciting and that is  way I did not mention it in my weekly outlook. I would hope 
you might be right  and that the meteors may bright....time will tell. 




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Dear Bob (and everyone else):
 
I've had a chance to look at this a little more  carefully over this 
weekend and believe that those of us near and  along the Atlantic Coast have at 
least a fighting chance to see an interesting,  albeit brief Leonid display 
early on Tuesday morning. Looking at  the plot developed by Jeremie 
Vauballion, we can see that the  Earth clearly should interact with a filament of dust 
shed by comet 55/P  (Tempel-Tuttle) dating back to AD 1400.  
 
See: 
_http://www.imcce.fr/langues/en/ephemerides/phenomenes/meteor/DATABASE/Leonids/BIN-tout/Noeuds-Earth2012.jpg_ 
(http://www.imcce.fr/langues/en/ephemerides/phenomenes/meteor/DATABASE/Leonids/BIN-tout/Noeuds-Earth2012.jpg) 
 
In a private correspondence with me about this, Jeremie  commented that 
 
" . . . as you can see the density of particles  doesn't look very high. 
Maybe an outburst at best."  
 
I found two other cases that compares somewhat similarly  to the upcoming 
interaction, at least in terms of particle density.  Both  involve the Alpha 
Aurigids.  
 
In 1935, from Sonneberg, Germany, Cuno Hoffmeister and  A. Tuchgraeber 
reported an Aurigid outburst with a ZHR of 30. Activity  lasted about an hour.  
 
Compare Jeremie's plot for the 2012  Leonids with that 1935 Aurigid event:
_http://www.imcce.fr/langues/en/ephemerides/phenomenes/meteor/DATABASE/Alpha
-Aurigids/BIN-tout/Noeuds-Earth1935.jpg_ 
(http://www.imcce.fr/langues/en/ephemerides/phenomenes/meteor/DATABASE/Alpha-Aurigids/BIN-tout/Noeuds-Earth1935
.jpg) 
 
And in 1994, another Aurigid outburst apparently took  place, which was 
observed from Descanso, CA by George Zay and  Robert  Lunsford.  In WGN 22-6, 
December 1994, pgs. 224-226, it is noted that  activity lasted for 50-minutes 
with the radiant only 13-degrees above the  horizon. Both saw a flurry of 
about a dozen bright Aurigids, corresponding  to a ZHR of about 45.  
 
 
Compare Jeremie's plot for the 2012  Leonids with that 1994 Aurigid event:

_http://www.imcce.fr/langues/en/ephemerides/phenomenes/meteor/DATABASE/Alpha
-Aurigids/BIN-tout/Noeuds-Earth1994.jpg_ 
(http://www.imcce.fr/langues/en/ephemerides/phenomenes/meteor/DATABASE/Alpha-Aurigids/BIN-tout/Noeuds-Earth1994
.jpg)    
 
So comparing the 2012 Leonid plot to the  Aurigid plots of 1935 and 1994, 
perhaps a brief outburst is indeed  possible.  
 
For this upcoming Leonid event, Jeremie is forecasting  the peak with the 
1400 AD filament at 7:58 UT on Nov. 20.  From  my location at Putnam Valley, 
NY, the Leonid radiant will be 45-degrees above  the east-southeast horizon. 
 
On the other hand, Mikhail Maslov suggests a  peak at 5:36 UT.  That would 
mean a much lower radiant  altitude for me . . . just 18-degrees.  Although 
that would mean fewer  meteor sightings, it also suggests meteor 
trajectories that could be rather  long. 
 
Regarding meteor brightness, this presumed comet dust is  over 600-years 
old and are now into their 18th revolution around the Sun. It is my contention 
that this whole process is similar to a miner  prospecting for gold . . . 
as he patently sits there shifting his  pan, with the passage of time the 
fine sand and  grit gradually disperse through the screen in the pan; in the 
end --  if he's lucky -- he might end up with a nugget or two.   

So maybe . . . just maybe . . . after all these hundreds  of years, the 
tiny dusty material from 1400 AD has chiefly dispersed  and perhaps what's left 
are a few pebble or marble-sized pieces . . .  which might create a few 
outstandingly bright  meteors.  
 
So that's the hope.  Will this actually come to  fruition?
 
I guess we'll all know when the Sun comes up on  Tuesday.

 
Good Luck to all!
-- joe rao
 
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