LASCO Activity Report for
September 13, 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

SOHO entered the Telemetry keyhole on 2004/09/11. It will last until
2004/10/06.

LASCO is loaded with the 2 hr cadence in C2 and C3 pB orange filter binned
full field (FOV) LEB summed.  This will be part of the CME Watch in LASCO
pB program to run the duration of this keyhole. This kicked off 9/10
22:30 UT and continues through 10/3 12:00 UT.

EIT 195 CME was interrupted on 2004/09/10 (Friday) at 20:00 UT for EIT CCD
bakeout calibrations. EIT CCD bakeout between 2004/09/10 @ 22:00 UT - 
2004/10/03 (Sunday) @ ~22:00 UT.

2004/09/10 (Friday)

00:30 UT  E Limb	Faint, ragged, and not well defined front. GOES recorded
			a C1.0 X ray flare from NOAA AR 10672 between 21:59 -
			22:26 UT with peak emission at 22:16 UT (on 2004/09/09).

08:06 UT  WS West	Faint (initially asymmetric) loop front. It fades
			throughout C3.

09:30 UT  E Limb	Couple of faint fronts in the gusty outflow, most 
			likely related to activity on NOAA AR 10672.

20:34 UT  E Limb	Initially bright ragged front. GOES recorded a C1.7 
			X-ray flare from NOAA AR 10672 (N01E59) between 18:56 -
			20:15 UT with peak emission at 19:41 UT.

21:49 UT  W Limb	Ragged loop front followed. It fades throughout C3.

2004/09/11 (Saturday)

03:36 UT  W Limb	Faint ragged loop front already under development. It
			fades throughout C3.

04:54 UT  W Limb	Small and faint ragged loop front developing slightly
			toward WSW.

05:12 UT  E Limb	Elongated and ragged faint loop front with apparently
			twisted trailing material.

08:12 UT  W Limb	Another couple of faint loop fronts becomes discernible.

	11:56 - 18:15 UT	Temporary Data Gap.

2004/09/12 (Sunday)

00:36 UT  E Limb	Bright loop front that develops as an off-centered 
			halo CME. A strong cavity and inner core can be well
			distinguished by 01:24 UT. At that time the LE on E 
			is already above the end of C2 FOV, and fainter loop-
			like extensions already cover the C2 occultor, spanning
			from the N to the S Pole, all above the W Limb. Much
			trailing material follows on E. The event is first seen
			on C3 at 01:18 UT above the E Limb. By 02:18 UT the C3
			occultor is completely covered, the LE on the E Limb
			being at ~ 13 solar radii, while on W the LE is only at 
			above 5.5 solar radii from disk center. For reference,
			the mean plane-of-sky speed for the LE of the outermost
			feature at various PA is given below (based on C3 data):
			PA 044 : 1150 km/sec 
			PA 086 : 1262 km/sec
			PA 140 : 1326 km/sec
			PA 221 :  787 km/sec
			PA 296 :  470 km/sec
			GOES recorded an M4.8 X-ray flare from the NOAA AR 
			10672 (N03E49) between 00:04 - 01:33 UT with peak
			emission at 00:56 UT. Please note that SOHO entered a
			telemetry keyhole on 2004/09/11 that will last until
			2004/10/06. Between 2004/09/10 22:00 UT - 2004/10/03
			22:00 UT EIT will be performing the CCD bakeout and
			therefore no EIT images will be available during that 
			period. The event has therefore been determined as an
			off-centered 'full' halo CME, most likely frontsided 
			in spite of the temporal correlation observed with the
			X-ray event. 
 
02:54 UT  E Limb	In the trailing material of previous event, a small and
			bright front can be discerned. It fades throughout C3.

12:12 UT  WS West	Very elongated loop front.

	12:54 - 19:12 UT	Temporary Data Gap.

19:36 UT  W Limb	Couple of faint loop fronts, one developing toward W
			(fades in C3) and the other one slightly toward WNW
			(fades in C2).

20:12 UT  N East	Faint ragged loop front that fades throughout C2. It is
			followed at 22:54 UT by a kind-of faint half loop front. 

2004/09/13 (Monday)

02:48 UT  N East	Ragged expanding front.

	09:45 - 17:00 UT	Temporary DSN Data Gap.