LASCO Activity Report for
December 30, 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

2005/12/26 (Monday)

15:30 UT  N Pole	Faint jet-like front.

19:31 UT  EN East	Very faint ragged front starts to be discernible 
			already half way across the C2 FOV. Very difficult to
			give an exact time of first appearance.

2005/12/27 (Tuesday)

00:06 UT  EN East	'Pair formation' in the trailing part of the event 
			reported to start at 19:31 UT on previous day (at ~
			4 solar radii, PA ~ 51). Difficul to give an exact
			time of occurrence.

08:54 UT  N East	Faint blob-like front. It fades throughout C3.

18:30 UT  N East	Very narrow fan-like front. It fades throughout C2.

20:30 UT  N Pole	Diffuse jet-like front followed by a similar event at
			20:58 UT. 

2005/12/28 (Wednesday)

03:06 UT  S East	Diffuse brightening precedes the development of a big
			and expanding loop system. The diffuse brightening 
			develops then as a diffuse loop front, wider than
			the loop system behind. By 06:30 UT, narrow and 
			ragged fronts start to be seen apparently pushing the 
			loop system from behind. In particular at 06:30,
			07:54, 08:54, 09:54, and 11:54 UT. The diffuse loop 
			front is first seen in C3 all above the SE limb at 
			04:42 UT, followed at 05:18 UT by the loop system. 
			The mean plane-of-sky speed of the LE of the diffuse 
			loop front at PA 150 was ~ 374 km/sec, showing
			practically no acceleration. The whole event spans 
			in the C3 FOV at 10:20 UT about 115 deg (from around 
			PA 085 - 200). No significant X-ray activity was 
			recorded by the time.

18:30 UT  S East	Narrow front at the southern leg of a fainter loop 
			front. It fades throughout C3.

22:30 UT  S East	Diffuse loop front followed at 23:54 UT by a blob-like
			front on its southern leg, moving apparently faster. 
		
23:30 UT  EN East	Faint and diffuse loop front that quickly fades. GOES
			recorded a C1.2 X-rayy flare on NOAA AR 10843 (N11E38)
			between 22:27 - 22:50 UT with peak emission at 22:38 UT.

2005/12/29 (Thursday)

	  S East	Intermittent ragged fronts moving toward the S Pole
			continue.

11:30 UT  S East	Complex Event (difficult to disentangle the sources of
			the different components): 
		      - Diffuse brightening, apparently the top of a system 
			of loops that develops rather slowly. 
		      - By 14:06 UT, a fainter and more diffuse loop front 
			(also wider) develops superposed in the LOS, moving
			faster.
		      - By ~ 16:54 UT, a bright and relatively narrow and slow
			loop front follows (much brighter to S) [hereafter 
			Structure #1]. 
		      - By ~ 20:58 UT, an asymmetric and expanding wide loop
			front with inner material develops behind (moving
			faster), extending up to past the S Pole (difficult to
			give an exact time of first apearance) [hereafter
			Structure #2]. Some trailing material. Structures #1
			and #2 seem to develop superposed on one another in
			the C3 FOV. The complex structure is first seen in C3
			above the SE limb at 21:18 UT developing as an
			asymmetric and expanding complex loop front. The mean
			plane-of-sky speed of the complex structure at its
			outermost part (at ~ PA 150) was ~ 480 km/sec, though
			exhibiting a marked acceleration. The complex structure
			spans ~ 125 deg in the C3 FOV at 03:42 UT on next day
			(from ~ PA 100 - 225). Therefore, it can be catalogued
			as a Partial Halo Event. EIT 195 images show the 
			formation of a small dimming region at around S15E05,
			extending toward S and starting at ~18:00 UT. Afterward,
			an expanding arcade forms above an extended filament
			channel located just South-East of disc center, probably
			indicating a filament eruption. GOES did not record
			significant X-ray activity by the time. However it did
			record a C1.1 X-ray flare on NOAA AR 10843 (N11E17)
			between 20:36 - 21:28 UT with peak emission at 21:06 UT
			(difficult to establish its connection with the LASCO
			event). In summary, the latter has therefore been
			determined as a Partial Halo Event, probably frontsided
			(as based on the EIT signatures).

2005/12/30 (Friday)

See Report on Dec. 31, 2005.