LASCO Activity Report for
July 8, 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

On 2005/07/06, SOHO Telemetry Submode was changed to Submode 5 (support for
VAULT -Sounding Rocket Launch on 2005/07/07). Telemetry Submode will be
changed back to Submode 6 on 2005/07/08 at 15:00 UT.

During TM Submode 5, EIT 195 CME watch in half-res (512x512).

2005/07/07 (Thursday)

04:06 UT  EN East	Slow development of a system of loops along streamer.
			The event superposes in the LOS with the Partial Halo
			under development reported to start at 21:26 UT on
			previous day.	

NOTE:

LASCO/EIT observed two frontsided events on 2005/07/07, which were
likely associated with: i) the eruption of a filament south of NOAA 
AR 10786, starting at 11:00 UT (EIT 195 time), hereafter Event "A", 
and ii) an M4.9 X-ray flare on NOAA AR 10786 (N09E03) that peaked at 
16:29 UT (hereafter event "B").

12:06 UT  S East 	Likely signatures of event "A" were first seen in C2 at
			12:06 UT above the SE limb, as a very faint and diffuse
			front [1]. Note that by 12:26 UT, a slightly brighter
			front (also diffuse) appears above the E Limb. This
			particular front could be be associated with activity 
			on NOAA AR 10789 at N17E48 (see below). Finally, by 
			13:26 UT, a wide loop-like expanding front [2] makes 
			its appearance above the SE limb preceded by a small
			front (~ 12:50 UT) on E. The event seems to barely
			surround the C2 occulting disk by just 16:06 UT, just
			before the appearance of the event associated with the
			M4.9 X-ray flare. The diffuse front [1] is first seen 
			in C3 at 12:42 UT above the ESE Limb, preceding the
			expanding loop front [2] at 14:42 UT on SE. It is
			difficult to say whether the event in C3 covers the C3
			occulting disk, partly due to the appearance in the C3
			FOV at 17:42 UT of the brighter and apparently faster
			event associated with the M4.9 X-ray flare. The mean
			plane-of-sky of the LE of [1] was 657 km/sec at PA 108
			(big uncertainty in its determination as LE too diffuse).
			As for the front [2], its mean-plane-of-sky speed was
			456 km/sec at PA 132. Both cases based on C3 data. GOES
			reported the following X-ray events by the time:
			- a C2.6 X-ray flare on NOAA AR 10789 (N17E48) between
		 	12:18-12:55 UT with peak emission at 12:29 UT, and  
			- a C3.8 X-ray flare on NOAA AR 10786 (N10E04) between
			13:25-13:34 UT with peak emission at 13:29 UT.
			EIT 195 images show the eruption of a filament just a
			little bit south of AR 10786, starting at ~ 11:00 UT.
			Corresponding running difference images show the 
			ejection of material toward SE. In summary, the event 
			has been determined as at least a partial halo CME 
			(maybe a very asymmetric full halo event) most likely
			associated with the eruption of a filament practically 
			at the center of the disk.

17:06 UT  E Limb	Event "B": The event was first seen in C2 at 17:06 UT 
			all above the E limb, as a wide and ragged front
			(emission brighter on ENE as it develops). By 18:50 UT,
			the C2 occulting disk seems to be completely covered, 
			though the signal is extremely faint on the western
			hemisphere. The event is first seen in C3 at 17:42 UT
			above the NE Limb, developing afterward as a very
			asymmetric halo CME. The mean plane-of-sky of the LE 
			of the event at PA ~ 25 was ~ 744 km/sec (based on C3
			data). GOES reported an M4.9 X-ray flare on NOAA AR 
			10786 (N09E03) between 16:07 - 16:40 UT with peak
			emission at 16:29 UT. For completeness, note that there
			was also a C2.7 X-ray flare on NOAA AR 10789 (N17E44)
			between 14:37 - 15:34 UT with peak emission at 15:19 UT.
			EIT 195 images show a relatively strong brightening
			starting at ~ 16:12 UT on AR 10786. A dimming region to
			NE of AR 10786 can be seen afterward. Corresponding 
			running difference images show an intensity disturbance
			traveling mainly toward N of the AR. In summary, the
			event has therefore been determined as a rather
			asymmetric full halo CME, associated with an M4.9 X-ray
			flare on NOAA AR 10786.

22:06 UT  N East	Faint and asymmetric expanding loop front. It fades 
			throughout C3.

2005/07/08 (Friday)

07:27 UT  N East	Elongated loop front developing toward ENE.

Time of the last C2 image under analisys: 11:26 UT.