LASCO Activity Report for
July 28, 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

2005/07/27 (Wednesday)

01:31 UT  WN West	Bright and elongated ragged loop front. EIT 195 images
			show signatures of a backsided CME above the ENE limb 
			(developing toward NW) starting at 01:13 UT.

04:54 UT  E Limb	Bright loop front. Faint and diffuse extensions to N 
			and S can be seen by 05:08 UT. By 06:06 UT, the C2
			occulting disk appears fully covered (by that time, 
			the LE on E is already well past the outer edge of C2).
			Prominence material follows the outer front on ENE. 
			Note that by 07:54 UT, a new bright loop-like front
			follows behind the trail of the prominence. The event 
			is first seen in C3 at 05:18 UT as a very bright loop
			front on E, with faint and diffuse extensions to N and 
			S. By 06:18 UT, the C3 occulting disk seems to be fully
			surrounded by these faint extensions (though they are
			very faint on the western hemisphere). The diffuse
			structures on west that made the C2 occulting disk to
			appear covered by 06:06 UT, are first seen in C3 by 
			07:42 UT on W and SW. The mean plane-of-sky speed of 
			the LE of the outermost front at PA ~ 83 was ~ 1960
			km/sec, showing practically no acceleration (based on 
			C3 data). GOES reported an M3.7 X-ray flare on N11E90
			between 04:33 - 05:30 UT with peak emission at 05:02 UT.
 			The source region is still behind the limb and is
			apparently located in the position of the old NOAA AR
			10786. EIT 195 images show the slow and gradual increase
			of a system of loops barely anchored behind the limb
			starting at around 03:48 UT, with a sudden brightening
			increase at 04:36 UT, just on the ENE limb. By 04:48 UT,
			the images show release of prominence material, jointly
			with a strong intensity disturbance all above the 
			eastern limb. A slight intensity disturbance can be 
			seen on the eastern part of the disk afterward. Post-
			plare loops can also be seen developing just above
			the limb. By 07:13 UT, another CME signature develops
			above the ENE Limb (also barely backsided). In summary,
			the event has therefore been determined as a strong
			limb event (barely backsided), with an associated 
			shock that made the event to look like an asymmetric 
			full halo event. The event was associated with an M3.7
			X-ray flare on the apparently old location of the former
			NOAA AR 10786 (barely behind the ENE limb). The location
			of this active region makes the arrival of a CME-
			produced interplanetary disturbance to the Earth
			unlikely.

07:54 UT  EN East	In the trailing material of previous event, a new bright
			and ragged loop-like front can be seen. EIT 195 images
			show by 07:13 UT a CME signature developing above the 
			ENE Limb (barely backsided).

11:06 UT  EN East	Small and bright ragged front in the southern part of 
			the trailing material of previous event. Gusty outflow
			continues. GOES reported a C1.7 X-ray flare on N14E88
			between 10:31 - 11:30 UT with peak emission at 10:55 UT.

	15:00 - 17:00 UT 	No LASCO C2/C3 CME watch images.
				High Cadence C3 PBs subfield images  for the
				Faraday Rotation Study with Cassini Campaign.

17:30 UT  EN East	Faint and ragged loop front already under way after gap.

22:30 UT  E Limb	Faint and elongated loop front preceding following 
			important event.

2005/07/28 (Thursday)

00:30 UT  E Limb	Bright and ragged front immediately followed on ENE by
			a narrower and also bright ragged front. GOES reported:
			i) on previous day, a C4.5 X-ray flare on N06E89 between 
			22:39 - 23:15 UT with peak emission at 23:00 UT, and
			ii) today, an M1.0 X-ray flare on N07E89 between 00:01 -
			00:54 UT with peak emission at 00:30 UT.

06:54 UT  EN East	Bright and relatively elongated ragged front. Twisted 
			trailing material. GOES reported a C2.8 X-ray flare on
			N11E79 between 06:13 - 06:52 UT with peak emission at
			06:52 UT.

Time of the last C2 image under analyis: 12:30 UT.