LASCO Activity Report for
December 15, 2006 SOHO Science Daily Meeting

Event times are first frame seen in C2 camera unless otherwise noted.
These are preliminary observations for the daily SOHO science discussions.
Final analysis is reported on the Lasco CME list.
An archive of these reports is available.

Points Of Interest

2006/12/14 (Thursday)

NOTE 1:
------
Proton storm slowly subsiding.

02:58 UT  EN East	Ragged (elongated) loop front developing gradually.
			Some gusty outflow along the day.

20:30 UT  WS West	Diffuse ragged front later surpassed by the following
			event.

22:30 UT  WS West	LASCO/EIT observed what would appear to be an 
			asymmetric Full Halo Event on 2006/12/14-15 
			(incomplete LASCO imagery by the time of writing).
			The event was first seen in the LASCO C2 FOV on 
			12/14 at 22:30 UT as a very bright loop front on 
			the WSW Limb with diffuse extensions to N. By 23:30 
			UT, the bulk of the CME (which heads toward SW as
 			projected onto the plane of the sky) reached the outer
 			edge of the C2 FOV, while the diffuse extensions (on 
			W) are already well past the outer edge. An increase 
			of cosmic rays can be seen by this time. The event is
 			first seen in C3 on 12/14 at 23:42 UT, all above the 
			SW Limb with faint and diffuse extensions to the sides
 			of the bulk of the CME. The mean plane-of-sky speed 
			for the LE of the bulk of the CME at PA ~ 237 was 
			about 970 km/sec. On the other hand, if measured on 
			the LE of the extensions surrounding the bulk of the 
			CME at PA ~ 263, the plane-of-sky speed amount ~ 
			1220 km/sec. Note that the measurements were based on
 			only a couple of C2 and C3 frames due to the no
 			availability of the "reformated" LASCO data at the 
			time of writing (we had yesterday a disk failure on 
			one of the LASCO operations machines and are right 
			now in the process of recovering). GOES recorded a 
			X1.5 X-ray flare on NOAA AR 10930 (S06W46) on 12/14
			between 21:07 - 22:26 UT with peak emission at 
			22:15 UT. EIT 195 images show a brightness increase 
			on AR 10930 at 22:00 UT, the brightening becoming\
			strongest at 22:12 UT. A rather circular wave (and
			dimming) with epicenter on the AR mentioned can be 
			seen afterwards, developing almost all the way to the
 			far Limb (East). By 23:12 UT, a slight increase on
		 	cosmic rays can be detected on EIT 195 images. In
			summary, based on the few LASCO images available the
			event has therefore been determined as a potentially
 			asymmetric full halo event, frontsided associated to 
			the X-class event that occurred late on 12/14 on AR
 			10930.

Last C2 image available by the time of writing: 23:30 UT

2006/12/15 (Friday)

No images available yet (computer maintenance).