LASCO Activity Report for
September 12, 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

KEYHOLE OPERATIONS:
-------------------
SOHO keyhole #10 telemetry period: Aug 31-Sep 28, 2005.

EIT will go to CCD bakeout between Sep 2 23:00 UT - Sept 23 10:00 UT 
with its mini-cal pre and post sets as folows:
2005/09/02 19:00:00 - 2005/09/03 01:00:00
2005/09/23 20:00:00 - 2005/09/24 00:20:00

During the Telemetry Keyhole LASCO will be in improved synoptic cadence 
of C2 at 12 mins cadence and C3 at 30 mins cadence, including daily 
orange/blue filter fielding images.

The SOHO rolled back to 0 deg on Thursday Sept 8, 2005. LASCO was safe for 
the S/C roll (also Station Keeping -SK- and Momentum Management -MM-) between
Wed Sept 7 at 11:00 UT - Friday Sept 9 at 12:00 UT.

2005/09/09 (Friday)

NOTE: 
----
After SOHO roll back to 0 deg (and SK and MM) on Thu Sept. 8, 2005,
LASCO resumed the CME watch on Friday Sep. 9 at 12:00 UT, the first
C2 image available being taken at 12:21 UT. The images look highly
degraded by the ongoing proton storm initiated after the X17 X-ray
flare from NOAA AR 10808 (old 10798) on Wed Sep 7, and apparently 
intensified by the high X-ray and CME associated activity that 
followed afterward. Some faint events maybe missing.

19:48 UT  ES East	Bright an asymmetric loop front on the ESE Limb. 
			Next frames show the main loop structure surrounded
			by a faint and diffuse envelope. This diffuse envelope
			seems to fully cover the C2 occulting disk by 20:12 UT
			(LE on SE already past the end of the C2 FOV). Much 
			gusty outflow on SE afterwards. The event is first seen
			in C3 at 20:18 UT spanning all the way from the NE limb
			up to past the S Pole (counterclockwise). By 20:42 UT,
			the C3 occulting disk is fully surrounded. The mean
			plane-of-sky speed of the outermost front at PA 100 was 
			~ 2300 km/sec. Following the X17 X-ray Event on Sep. 7
			from NOAA AR 10808 (peak at 17:40 UT) GOES recorded on
			Thu Sep. 8 multiple C-class X-ray activity in addition 
			to the following X-ray flares (all from AR 10808):
			- an M2.1 (S12E74) between 16:49 - 17:11 UT (peak at
			  17:03 UT),
			- another M2.1 (S12E70) between 20:23 - 20:49 UT (peak
			  20:41 UT), and
			- an X5.4 (S12E75) between 20:52 - 21:17 UT (peak at
			  21:06 UT).
			On Fri Sep 9, multiple C-class activity continues plus
			the following X-ray flares (all from NOAA AR 10808):
			- an M1.0 (S13E68) between 02:08 - 02:29 UT (peak at
			  02:19 UT),
			- an M1.1 (S12E68) between 02:33 - 02:39 UT (peak at
			  02:36 UT),
			- an X1.1 (S12E68) between 02:43 - 03:07 UT (peak at
			  03:00 UT),
			- an M1.8 (S10E67) between 04:46 - 05:12 UT (peak at
			  05:03 UT),
			- an M6.2 (S13E71) between 05:32 - 06:00 UT (peak at
			  05:48 UT),
			- an X3.6 (S11E66) between 09:42 - 10:08 UT (peak at
			  09:59 UT).
			Unfortunately, there were no LASCO images up to noon 
			UT on 09/09. Therefore, we can say nothing about the
			potential CME events associated with those X-ray events.
			Later in the day (Sep 9) GOES recorded:
			- an M1.9 (S11E60) between 17:32 - 18:10 UT (peak at
			  17:51 UT), 
			- an X6.2 (S12E67) between 19:13 - 20:36 UT (peak at
			  20:04 UT).
			The latter is the X-ray event most likely associated 
			to the event observed by LASCO. Due to the EIT CCD
			bakeout, there were no EIT images. In summary, the event
			has therefore been determined as an asymmetric Full 
			Halo Event, frontsided, associated to an X6.2 X-ray 
			flare from AR 10808.

2005/09/10 (Saturday)

NOTE:
----
LASCO images still look highly degraded by the ongoing proton.
Some faint events maybe missing.

07:17 UT  S East	Elongated loop front.

21:52 UT  S East	Bright and asymmetric loop front on the SE Limb. Next
			frames show the main loop structure surrounded by a 
			faint and diffuse envelope. This diffuse envelope seems
			to fully cover the C2 occulting disk by 22:07 UT (LE 
			on ESE already past the end of the C2 FOV). Pseudo-
			continuous outflow on SE afterward, moving toward the
			S Pole. The event is first seen in C3 at 22:15 UT
			spanning all the way from the NE limb up to past the 
			S Pole (counterclockwise). By 23:41 UT, the C3 occulting
			disk is fully surrounded. The mean plane-of-sky speed of
			the outermost front at PA 115 was ~ 1750 km/sec (take
			into account that the proton storm plus the faintness 
			of the outermost front contribute to certain uncertainty 
			in the speed determination). On Sat Sep 10, multiple
			C-class activity continues. On top of that, the 
			following X-ray flares (all from NOAA AR 10808) were
			recorded by GOES:
			- an M3.7 (S11E51) between 06:06 - 06:17 UT (peak at
			  06:14 UT),
			- an M1.9 (S12E51) between 08:59 - 09:31 UT (peak at
			  09:07 UT),
			- an X1.1 (S11E47) between 16:34 - 16:51 UT (peak at
			  16:43 UT),
			- an M4.1 (S12E45) between 19:10 - 19:50 UT (peak at
			  19:36 UT), and
			- an X2.1 (S13E47) between 21:30 - 22:43 UT (peak at
			  22:11 UT).
			The latter is the X-ray event most likely associated 
			to the event observed by LASCO. Due to the EIT CCD
			bakeout, there were no EIT images. In summary, the event
			has therefore been determined as an asymmetric Full 
			Halo Event, frontsided, associated to an X2.1 X-ray 
			flare from AR 10808.

2005/09/11 (Sunday)

NOTE:
----
LASCO images still look highly degraded by the ongoing proton storm, 
though not as much as before. The proton storm seems to be slowly decaying.

13:00 UT  ES East	Bright loop front just appearing above the ESE Limb.
			It develops as a bright and wide loop front toward SE
			with some faint and  diffuse extensions that make the
			whole event appear wider. By 13:48 UT, the whole event
			spans in C2 ~ 240 deg (from PA 20 to 260). The signal 
			is too faint on NW to be certain whether the event
			reaches to fully cover the C2 occulting disk. Gusty
			outflow on SE afterward. The event is first seen in C3 
			at 13:36 UT all above the SE Limb. By 14:42 UT, the C3
			occulting disk seems to be fully covered, on NW by very
			faint and diffuse extensions. The mean plane-of-sky 
			speed of the outermost front at PA 110 was about 
			1960 km/sec (based on C3 data). On Sat Sep 11, GOES
			continued recording multiple C-class X-ray activity 
			from NOAA AR 10808. It also recorded on the same AR an
			M3.0 X-ray flare (S16E39) between 12:44 - 13:53 UT 
			with peak emission at 13:12 UT. The M flare is the X-ray
			event most likely associated to the event observed by 
			LASCO. Due to the EIT CCD bakeout, there were no EIT
			images. In summary, the event has therefore been
			determined as an asymmetric Full Halo Event, frontsided,
			associated to an M3.0 X-ray flare from AR 10808.

20:57 UT  S East	In the aftermath of previous Halo, a diffuse and ragged
			loop front can be discerned. GOES recorded an impulsive
			M1.3 X-ray flare on NOAA AR 10808 between 20:29 - 20:49
			UT with peak emission at 20:40 UT.

2005/09/12 (Monday)

NOTE:
----
Proton storm finally subsiding.

	  S East	Some gusty outflow all along the day.

Last C2 image under analysis: 14:24 UT