LASCO Activity Report for
July 23, 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

2004/07/22 (Thursday)

01:31 UT  S Pole	An initially bright front is seen rising on the S Pole 
			in C2, with fainter loop-like extensions above the SW
			Limb, and followed by much outflow on the S Limb. Later,
			by 05:30 UT, a ragged loop front can be discerned in 
			the trailing material. C3 shows the development of the
			event as, apparently, two superposed ragged loop-like
			structures, one moving mainly toward S and the other
			slightly toward NW. Globally, the event spans in C3 
			~ 100 deg at 07:42 UT, from PA ~ 140 - 240. The mean
			plane-of-sky speed was around 500 km/sec, as measured 
			at PA ~ 180 and based on C3 data.
			GOES recorded a M9.1 X-ray flare on NOAA AR 0652 (N03E13)
			between 00:14 - 00:43 UT with peak emission at 00:32 UT.
			EIT Fe XII running difference images record a strong
			brightening on AR 0652 starting at 00:24 UT and peaking
			at 00:36 UT. Another brightening occurs at 04:00 UT.
	
07:31 UT  S Pole	Complex Event: Basically, at 07:31 UT a bright narrow 
			feature appears above the S Pole in C2, preceding the 
			development of an asymmetric loop front at the S Pole
			with faint loop-like extensions above the SW Limb. By
			that time, an extremely faint and diffuse arcade-like
			front can be discerned in C2 developing mainly toward 
			NE, jointly with another similar one toward NW. Their
			faintness makes it difficult to establish the exact 
			time of first appearance. On the other hand, C3 shows,
			starting at 07:42 UT, the development of a faint and
			diffuse wide loop front on NNE; and starting at 08:42 UT
			a wide ragged loop front developing on SSW. The former
			seems to surround later the occultor. The mean plane-
		 	of-sky speed was around 913 km/sec, as measured at 
			PA ~ 210; and ~ 652 km/sec as measured at PA ~ 30 
			(based on C3 data).
			GOES recorded by the time several C-class X-ray flares 
			on NOAA AR 0652:
			C1.7 (N05E13) between 06:33 - 06 43 UT; Peak at 06:38 UT
			C2.1 (N04E12) between 06:54 - 07:07 UT; Peak at 07:00 UT
			C5.5 (N03E08) between 07:41 - 08:10 UT; Peak at 07:59 UT
			Fe XII running difference images show discernible
			brightenings on AR 0652 at 06:36 UT and 07:48 UT (no
			images between 06:48 - 07:13 UT). No significant dimming
			or wave is observed in association with the C-class
			events. This event has therefore been determined, from 
			a global point of view, as a faint 'full' halo CME.

08:54 UT  S West	Ragged loop front that fades throughout C2.

11:54 UT  S Pole	Diffuse and ragged loop front followed at 12:30 UT by a
			small bright front and gusty outflow. At ~14:30 UT in 
			the gusty outflow begins to be discernible a loop front.
			It fades throughout C3.

13:54 UT  WN West	Very faint elongated and ragged loop front. It fades 
			throughout C2.

17:54 UT  NN East	Faint and diffuse jet-like front that quickly fades.

17:54 UT  S Pole	Spray front followed at ~ 19:34 UT by a kind of
			asymmetric loop front. They both fade throughout C3.
			C3.2 X-ray flare on NOAA AR 0652 (N04E07) between
			17:17 - 17:37 UT (Peak at 17:24 UT).

23:54 UT  SS West	Diffuse and not well defined loop front. At 00:06 UT 
			on next day, bright narrow feature superposed with 
			the loop's leg on the S Pole. Gusty outflow follows
			toward S. At 01:54 and 02:30 UT couple of asymmetric 
			loop fronts developing toward SSW. GOES recorded 
			C- and M-class X-ray flares by the time:
			C4.1 (N03E04) between 22:01 - 22:18 UT; Peak at 22:12 UT
			M1.6 (N04E03) between 22:40 - 23:07 UT; Peak at 22:58 UT
			C1.3 (N03E02) between 23:09 - 23:45 UT; Peak at 23:21 UT
			Fe XII running difference images show discernible
			brightenings on AR 0652 at 22:12 UT and 23:24 UT (no
			images between 22:36 - 23:12 UT).

2004/07/23 (Friday)

03:30 UT  W Limb	Very very slow development of an apparently twisted
			structure.

03:54 UT  E Limb	Ragged loop front. Superposed with it, a very diffuse
			and faint loop-like feature seems seems to develop,
			moving faster. Barely visible in C3. 

07:31 UT  S West	Diffuse and not well defined loop front. Difficult
			to give an exact time of first appearance. Faint and
			diffuse loop-like front starting at ~08:30 UT above 
			the W Limb. GOES recorded C-class X-ray flares by the
			time:
			C2.3 (N03W04) between 06:41 - 07:02 UT; Peak at 06:48 UT
			C4.3 (N03W04) between 07:17 - 07:36 UT; Peak at 07:26 UT
			Fe XII running difference images show discernible
			brightenings on AR 0652 at 06:48 UT and 07:36 UT.