LASCO Activity Report for
July 25, 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

2005/07/22 (Friday)

01:54 UT  N East	Very faint and elongated loop-like front.

02:30 UT  S East	Extremely faint and wide loop front. Just barely visible
			in C3 only very close to the inner edge of its FOV.
	
06:30 UT  N East	Ragged blob-like front in the gusty outflow.

09:54 UT  E Limb	Diffuse and elongated loop-like front.	

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

17:30 UT  S Pole	Extremely faint (almost circular) front spanning all the
			way from ENE, E, SE, S, SW, and NW, already under way
			after the gap. The event is first seen in C3 at 17:42 UT,
			above the SE Limb, fading out by arounf 20:25 UT. No 
			significant X-ray activity was reported by GOES during
			the day (A-class). 

17:54 UT  N East	Ragged and elongated loop front. It fades throughout
			C3.

23:54 UT  S East	Diffuse front on SE, with very faint and even more
			diffuse extensions above the E Limb, S Pole, and south
			western limbs. The bulk of the CME is seen developing
			then toward South, with very faint extensions (shock)
			above the N Pole. The event is first seen in C3 on
			2005/07/23 at at 01:42 UT, all above the eastern limb,
			S Pole, and western limb. Extremely faint extensions
			above the N Pole make the event to look like a symmetric
			full halo event, though the bulk of the CME seems to
			develop mainly toward S. The mean-plane-of-sky speed of
			the LE of the event at i) PA 128 was ~ 470 km/sec, and 
			at ii) PA 212 was ~ 400 km/sec. GOES reported extremely
			low X-ray activity by the time of the start of the event
			(A-class). Likewise, EIT 195 images do not show any
			significant activity on the disk. In summary, the event
			has therefore been classified as a full halo event,
			backsided. 

2005/07/23 (Saturday)

04:54 UT  N East	Elongated and relatively narrow loop front. Inflows
			all above the eastern limb.

09:30 UT  N East	Small and diffuse brightening develops as a ragged loop
			front.

12:30 UT  ES East	Diffuse and ragged loop front that partly superposed
			in the LOS with the trailing material of previous event.

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

17:43 UT  EN East	Faint and asymmetric expanding loop front already
(C3 Time)		under development in C3 after the gap.

19:54 UT  EN East	Small and narrow brightening develops as a bright loop
			front. The event is surpassed in the C3 FOV by the
			event reported to start at : UT.

20:58 UT  N West	Extremely faint and diffuse wide front that apparently
			fades throughout C2.

23:30 UT  EN East	Briagh and ragged front develops as an asymmetric front 
			expanding toward N. By 00:43 UT on next day, the event 
			spans up to past the  N Pole. It moves faster than the 
			event reported to start at 19:54 UT, surpassing it
			in the C3 FOV by around 03:18 UT.

2005/07/24 (Sunday)

04:54 UT  ES East	Faint and diffuse expanding loop front. It fades close
			to the inner edge of C3.

11:30 UT  ES East	Bright loop front develops as at least a Partial Halo
			Event. By 11:54 UT, faint extensions span up to above 
			the N Pole. By 12:43 UT, the whole event spans in C2
			about 210 deg (approximately from PA 310 - 160). It was
			first seen in C3 at 11:42 UT just appearing above the 
			ESE limb. The mean plane-of-sky speed of the LE of the
			bulk of the CME (not the diffuse front ahead, as it was
			too diffuse for an accurate measurement) was ~960 km/sec
			at PA 112. The event was apparently surpassed by the 
			Full Halo Event (see next entry) during the C3 gap. 
			EIT 195 images do not show frontsided activity during 
			the time of the start of the event. A faint CME 
			signature can be seen however above the E limb by 
			around 11:12 UT. This event is catalogued therefore 
			as at least a partial halo event, backsided.

13:54 UT  E Limb	Bright and ragged loop front develops as a Full Halo
			Event in the aftermath of the "at least" Partial Halo
			Event reported to start at 11:30 UT. The loop front
			develops as an expanding and bright loop front toward
			E, surrounded by diffuse extensions. The C2 occulting
			disk appears to be fully surrounded by 14:30 UT.
			Unfortunately, there are no C2 CME watch images between
			15:00 - 17:00 UT (last C2 image before the gap at 14:30
			UT, first one after the gap at 17:07 UT), because of
			especial C2 observations (only PBs subfield images) for
			the Faraday Rotation Study (with Cassini). The event 
			is first seen in C3 at 14:18 UT, all above the eastern
			limb. The next C3 image (17:18 UT) shows the LE on E
			apparently past the outer edge, with faint extensions
			above the western limb. Due to the lack of C3 images
			between 15:00 - 17:00 UT, it becomes practically
			impossible to determine the mean plane-of-sky speed of
			the LE on C3. Therefore, Using only 2 C2 frames and 
			one C3 frame, the mean plane-of-sky speed was about 
			2500 km/sec at PA 081, showing practically no
			acceleration. GOES reported extremely low X-ray activity
			during the whole day (A-class). Likewise, EIT 195 images
			do not show any significant activity on the disk.
			However, it does show an important (backsided) CME
			signature above the E Limb, starting at around 13:36 UT.
			In summary, the event has therefore been classified as 
			a strong and asymmetric full halo event, backsided. 

17:30 UT  E Limb	In the gusty outflow left by the Halo event, a ragged 
			loop front becomes discernible.

22:30 UT  E Limb	Bright and ragged loop front above the E Limb with very
			faint and diffuse extensions to N and S. The ragged 
			loop front develops toward ESE, the C2 occulting disk
			being fully covered by the extensions by ~ 23:54 UT 
			(by that time the LE on E is well past the outer edge 
			of the C2 FOV, while on W-SW the extensions are just
			above the inner edge of C2). The event is first seen 
			in C3 at 23:18 UT, all above the E-ESE limb. Faint
			expanding extensions can be seen then to S, and up to
			past the N Pole. Though the C3 disk becomes apparently
			fully covered by 02:18 UT, the signal is extremely 
			faint on SW. The mean plane-of-sky speed of the ragged 
			LE at PA 098 was ~ 650 km/sec. GOES reported extremely
			low X-ray activity during the 24th and 25th of July
			(A-class). Likewise, EIT 195 images did not show any
			significant activity on the disk. In summary, the event
			has therefore been classified as a very asymmetric full
			halo event, backsided. 

2005/07/25 (Monday)

11:06 UT  E Limb	Ragged front just appearing above the E Limb. By 11:30
			UT, the LE of the ragged front (now seen as a wide and
			ragged loop front) already reached the outer edge of C2.
			Faint extensions reach the W limb by 11:54 UT, the C2
			occulting disk being fully covered by 12:43 UT (the
			signal is again extremely faint above the SW limb). The
			event is first seen in C3 at 11:18 UT, just appearing
			above the E Limb. By 11:42 UT faint extensions cover 
			both the N and S poles. The C3 occulting disk is fully
			covered by 12:18 UT. The mean plane-of-sky speed of 
			the LE at PA 068 was ~ 1590 km/sec. GOES reported
			extremely low X-ray activity during the day (A-class). 
			Likewise, EIT 195 images did not show any significant
			activity on the disk. However, it did show signatures 
			of an important backsided CME all above the E Limb
			starting at around 11:00 UT. In summary, the event has
			therefore been classified as an asymmetric full halo
			event, backsided. 

Time of the last C2 image under analysis: 14:30 UT