LASCO Activity Report for
July 21, 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

2006/07/20 00:00 UT - 2006/07/28 24:00 UT --> EIT CME Watch Program in 171 A.

2006/07/20 (Thursday)

08:54 UT  WS West	Extremely faint and diffuse front (in fact, barely
			discernible). It quickly fades. EIT 171 images show
			formation of a dimming region to SW of AR 10900
			starting at ~ 08:00 UT. It develops toward NE.

13:54 UT  S East	Expanding and bright loop front, which is then 
			followed by a core develops as a Partial Halo Event. 
			The southern leg of the event crosses the S Pole by
 			around 16:06 UT. The event is first seen in C3 at 
			15:18 UT just appearing above the ESE limb. By 15:42 
			UT, the bright loop front of the event is clearly
		 	discernible. By 19:42 UT, the event spans in C3 ~ 
			160 deg (from PA 067 - 227), though it seems to 
			continue expanding. The mean plane-of sky speed of 
			the LE at PA 125 was ~ 375 km/sec showing a slight
 			acceleration (LE at 12.5 solar radii at the time of 
			measuring the speed -last frame used taken at 12:42
			UT-). GOES recorded no significant X-ray activity 
			during the day (A-level). EIT 171 images show the
 			eruption of a big filament that extends all the way 
			from the SE limb (apparently extending toward the
 			backside of the disk) to the central meridian (close 
			to the equator). The eruption seems to start at about
 			12:36 UT when a small brightening can be seen on the
 			disk close to the SE limb. Nice post-eruption loops
 			along the filament channel start to be seen by around
 			14:12 UT (centroid -most visible part- of the
			post-eruption loops at around S24E22). In summary, 
			the event was catalogued as a Partial Halo Event, 
			with an important frontsided component, associated to 
			a filament eruption on the SE quadrant (and possibly
 			extending behind the limb).

2006/07/21 (Friday)

	03:30 - 12:06 UT	Temporary Data Gap.

Last C2 image available by the time of writing:  12:30 UT