LASCO Activity Report for
July 20, 2004 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

2004/07/19 (Monday)

00:54 UT  E Limb	Wide expanding system of faint loops. Brighter material
			by 05:30 UT, at the PA of the southern leg of the system
			of loops developing as an elongated and ragged loop
			front. Gusty outflow.

09:30 UT  W Limb	Bright asymmetric loop front with inner core and 
			trailing material develops toward WNW. Starting at
			~08:48 UT EIT Fe XII running difference images show
			signatures of a big CME above the W Limb, apparently
			originated barely behind the disk.

13:30 UT  EN East	Partial Halo CME. The event was first clearly discerned
			in C2 at 13:30 UT spanning from ~ PA 320 - 170, just
			after a short data gap (12:06 - 13:30 UT). A bright 
			loop-like feature is also seen above the ENE Limb, 
			which develops exhibiting an apparently twisted trailing
			part. The mean plane-of-sky speed of the event as
			measured at the leading edge (LE) of the outermost 
			front at PA ~070, was ~270 km/sec (based on C3 data),
			showing a slight acceleration. On the other hand, the
			mean plane-of-sky speed of the LE of the bright loop on
			ENE was ~192 km/sec at the same PA (based on C2 and C3
			data), showing also a slight acceleration. 
			The event was likely associated with complex solar
			activity reported by GOES on the visible side of the
			solar disk, more precisely, related to activity above 
			the NOAA AR 0652, and to a lesser extent NOAA AR 0653.
		 	In particular, the C2.9 X-ray flare reported to occur
			between 10:47 - 10:55 UT with peak emission at 10:52 UT
			on AR 0652 (N07E42) was most likely associated to the
		 	event. It is also worth to mention the C2.5 X-ray flare
			occurred on NOAA AR 0653 (S12E52) between 13:00 - 13:22
			UT with peak emission at 13:14 UT. On the other hand, 
			EIT Fe XII running difference images show a brightening
			above AR 0652 at 10:48 UT with a dimming developing
			mainly NW afterward.

14:54 UT  WN West	Elongated bright front (dificult to establisg time of
			first appearance) develops as an expanding twisted
			structure. Starting at ~14:48 UT EIT Fe XII running
			difference images show signatures of a big CME above 
			the WNW Limb, coming out from behind the disk. Gusty
			outflow follows, well into next day.

20:30 UT  E Limb	Elongated ragged loop front in the trailing material 
			of the previous 'Partial" Halo CME.

2004/07/20 (Tuesday)

00:54 UT  E Limb	Initially bright ragged loop front that fades throughout
			C3.

04:30 UT  E Limb	Another ragged loop front (slightly brighter), with
 			apparently twisted trailing material.

04:54 UT  S East	Elongated and ragged loop front along streamer.