LASCO Activity Report for
May 21, 2007 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

KEYHOLE Operations:
-------------------
26 m keyhole: 2007/05/18 - 2007/06/05
34 m keyhole: 2007/05/21 - 2007/06/01

While in Keyhole, improved cadence in LASCO C2 (12 min) and 
LASCO C3 (30 mins). 

EIT CCD Bakeout starts on 2007/05/18 @ ~15:00 UT and ends on 2007/06/05.

Spacecraft Maneuvers on Tuesday 2007/05/29. 
(Station Keeping, Momentum Management, and 180 deg Roll.

LASCO will safe on 2007/05/28 @~ 12:00 UT and will recover 
on 2007/05/30 @~ 23:00 UT.

2007/05/18 (Friday)

	00:00 - 05:06 UT	LASCO Data Gap (C2 time).

05:06 UT  W Limb	Faint wisted structure can be discerned, following the
 			event reported to start at 16:30 UT on previous day.

	20:36 - 24:00 UT	LASCO Data Gap (C2 time).

2007/05/19 (Saturday)

13:24 UT  W Limb	Diffuse and wide faint loop front (see next entry).

13:48 UT  N West	Ragged expanding front -hereafter Front 1- at the
 			northern leg of previous event -hereafter Front 0- 
			(by this time Front 0 is almost at the edge of the C2
 			FOV). A very ragged front -hereafter Front 2- seems to
			follow behind by around 14:36 UT, quickly spanning 
			up to well past the N Pole. Front 1 (and 0) are first
			seen in C3 at 14:42 UT (front 1 just just appearaing);
			Front 2 does it at 16:18 UT. By 20:42 UT, the complex
 			event is no longer discernible in the C3 FOV (outermost
 			part -on NW- below 14 solar radii). GOES reported a 
			B9.5 X-ray flare from NOAA AR 10956 (~ N03W07) between
 			12:48 - 13:19 UT with peak emission at 13:02 UT. 
			NO EIT images available (EIT in CCD bakeout mode).
 

2007/05/20 (Sunday)

06:48 UT  SS West	Expanding loop front. Extremely faint extensions seem 
			to surround the C2 occulting disk, starting at about 
			07:36 UT. The event is first seen in C3 just appearing 
			above the SSW limb at 08:18 UT. The C3 occulting
			disk seems to be fully covered by 12:18 UT (signal on
			NE just above the limb, and in fact extremely faint).
 			By 13:42 UT the halo-like feature is not longer
 			discernible, only the bulk of the CME (loop-like 
			feature on SSW) remains discernible developing toward
 			SSW (and only until around 15:42 UT (LE below 16 solar
 			radii). The mean plane-of-sky speed of the LE of the
 			loop-like feature at PA ~ 200 deg is ~ 280 km/sec
 			showing practically no acceleration (based on C3 data).
 			GOES reported a B6.7 X-ray flare from NOAA AR 10956 
			(~ N02W20) between 04:52 - 06:20 UT with peak emission
 			at 05:56 UT. NO EIT images available (EIT in CCD 
			bakeout mode).

2007/05/21 (Monday)

	01:12 - 05:48 UT	LASCO Data Gap (C2 time).

Last C2 image available by the time of writing: 07:24 UT.