LASCO Activity Report for
January 19, 2007 SOHO Science Daily Meeting

Planner: K. Schenk, G. Stenborg

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




2007/01/18 (Thursday)

00:54 UT  NN East	Very faint (apparently expanding) loop front. Not 
			discernible in C3.

01:31 UT  WS West	Initially bright and elongated feature that fades
			throughout C3.

03:06 UT  S Pole	Faint loop front that fades throughout C3.

09:54 UT  W Limb	Ragged front.

	12:00 - 18:00 UT	NO LASCO CME watch program due to special
				C2 observation program (polar coronal hole/
				plumes study in the SOUTH: orange filter at
				100 sec exposure with a 5 minute cadence of
				the upper paret of the FOV -1024x416-).


2007/01/19 (Friday)

04:30 UT  E Limb	Full Halo Event. First seen as a very bright loop 
			front on the E Limb with diffuse extensions that
 			surround completely the C2 occulting disk by the 
			time of first appearance (04:30 UT). The bulk of 
			the CME (i.e., the brighter part of the front) develop
 			toward E as projected onto the plane of the sky, while
 			the diffuse extensions expand simetrically all around
 			the occculting disk. The event was first seen in C3 at
 			05:18 UT, all above the E Limb. The diffuse extensions
 			start to be seen on W by 05:18 UT, and by 06:18 UT the
 			C3 occulting disk appears fully surrounded (signal on 
			N barely above the occulting disk). The mean plane-
			of-sky speed at PA ~90 deg amounts ~ 570 km/sec, while
 			at PA ~260 deg the mean plane-of-sky speed is about 
			~620 km/sec (LE very diffuse and faint). Both
 			determinations were based on C3 data, and the
			height-time profile shows practically no acceleration).
			GOES recorded no significant X-ray activity prior and
 			during the LASCO event (A-level). EIT 195 running
 			difference images show, by around 04:36 UT above the 
			ENE Limb, what appears to be very faint signatures of 
			a backsided CME. No significant activity on the disk.
			In summary, the event has therefore been determined 
			as a full halo event, most likely backsided.

Last C2 image available by the time of writing: 12:00 UT.

	12:00 - 18:00 UT	NO LASCO CME watch program due to special
				C2 observation program (polar coronal hole/
				plumes study in the SOUTH: orange filter at
				100 sec exposure with a 5 minute cadence of
				the lower part of the FOV -1024x416-).



Web curator: K.M.Schenk
NASA Goddard Space Flight Center
Solar Physics Branch / Code 682
Greenbelt, MD 20771