LASCO Activity Report for
April 26, 2005 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

- SOHO is in telemetry Submode 5 (since 2005/03/11 @ 15:00 UT).

- EIT 195 CME watch at half-res (512x512).
 
- Venus entered the C3 FOV from the right on 2005/02/26 
  (by the end of the day). Still visible.

2005/04/25 (Monday)

04:26 UT  EN East	Expanding twisted structure embedded in the preexistent
			outflow. Difficult to give an exact time of first 
			appearance.

10:26 UT  NN East	Ragged and apparently twisted small feature, just 
			as little bit to N of the expanding twisted feature
			reported to start at 04:26 UT. 

11:06 UT  S West	Jet-like front that quickly fades.

13:50 UT  S West	Bright and elongated asymmetric loop front (spray-
			like) a little bit to N of the jet. It fades 
			throughout C3.
	
19:50 UT  S West	Bright, elongated, and very thin loop-like front.
			Faint expanding extensions to N.

23:06 UT  S Pole	Diffuse and wide loop front just appearing above the 
	  Partial	S Pole. A clear and well defined front can already 
	   HALO		be seen by 23:50 UT. Couple of faint and diffuse 
			fronts follow later, during the first hours of 04/26. 
			The bulk of the event spans in C2 at 01:27 UT (on 
			04/26) about 173 deg (from PA 107 - 280). The event 
			was first seen in C3 on 04/26 at 01:42 UT. The 
			angular span is kept during its evolution in C3. 
			The mean plane-of-sky speed of the LE of the event 
			(based on C3 data) at PA 206 was ~ 330 km/sec, showing
		 	practically no acceleration. EIT 195 images show the
			eruption of a filament on 2004/04/25 on the SW 
			quadrant (very close to the limb), associated with 
			the C2/C3 event. In particular, the filament begins 
			to rise by ~ 17:24 UT, initially very slowly. By 21:12
			UT, some post event loops start to be seen. The EIT 
			304 image taken on 2005/04/25 at 19:19 UT clearly 
			shows the filament already above the SW Limb. On the
			other hand, GOES reported no significant X-ray activity
			by the time. In summary, the event has therefore been
			determined as a partial halo CME, at least partly
			frontsided, associated with a filament eruption.

2005/04/26 (Tuesday)

Time of the last C2 image analized: 12:06 UT.