Halo CME Mail

Date: Wed, 13 Dec 2006 11:22

From: Guillermo Stenborg

Subject: Full Halo Event on 2006/12/13, frontsided


Status: O

UCMEO 93001 61213 1525/
61213 60254 80927 0001/ 360// 133// 21800
61213 60214 80257 32306 10930 1112/
99999
 
PLAIN
 

LASCO/EIT observed a Full Halo Event on 2006/12/13. The event was first 
seen in the LASCO C2 FOV at 02:54 UT as a very bright and wide loop front 
all above the S Pole, preceded by a diffuse front that fully surrounds 
the occulting disk (signal barely above the limb on N, almost at the end
of the C2 FOV on the S). An increase of cosmic rays (proton storm) starts
to be observed at 03:06 UT; by 03:34 UT the images are almost fully 
degraded by the ongoing proton storm. The event is first seen in C3 at 
03:18 UT, all above the S Pole. The bulk of the CME heads toward S (as
projected onto the plane of the sky). The C3 occulting disk is fully 
surrounded by 03:42 UT. The mean plane-of-sky speed of the LE (as 
measured at the edge of the brightest part of the LE) at PA ~ 190 deg 
was ~ 1440 km/sec. If measured at the outermost edge of the event (i.e.,
that of the diffuse front ahead of the bulk of the CME) the plane-of-sky
speed is ~ 1800 km/sec (both determinations based on C2 and only a 
couple of C3 frames - afterward images too degraded by the ongoing 
proton storm).

GOES recorded a X3.4 X-ray flare on NOAA AR 10930 (S06W23) between 
02:14 - 02:57 UT with peak emission at 02:40 UT. EIT 195 images show a 
sudden increase in brightness on AR 10930 by 02:24 UT. A rather circular
wave (and dimming) with epicenter on the AR mentioned can be seen
afterwards quickly covering the full disk.
 
In summary, the event has therefore been determined as a full halo event, 
frontsided.

Movies and images of the event will shortly be made available at: 

ftp://ares.nrl.navy.mil/pub/lasco/halo/20061213


Best wishes,

	Guillermo Stenborg

++
Dr. Guillermo A. Stenborg   
SOHO-LASCO Operations Scientist,                                           
CUA, MC 612.5, Bldg 26, Rm 001,   F: +1-301-286-0264         
NASA Goddard Space Flight Center,
Greenbelt, MD 20771.              P: +1-301-286-2941

e-mail: stenborg@kreutz.nascom.nasa.gov
+