Subject: SOHO/LASCO Partial HALO CME 110910a UCMEO 93001 10912 1713/ 10910 60312 81154 2361/ 077// 323// 40782 10909 62257 80518 42833 ///// 2212/ 99999 PLAIN SOHO/LASCO observed a Partial HALO CME on September 10, 2011. Event is first seen in C2 at 03:12 UT as wide bright loop centered at PA 329 degrees followed by multiple cores. The front expands with extensions PA 236-77 degrees for a total coverage of 201 degrees over the North East. The event continues into the C3 field beginning 04:06 to 11:54 UT out to the edge of view at 30 Rsun. Time/height measurements were marked at 9 points in C2 with speeds of 699.2 Km/sec at position angle 327 degrees. The event is marked to 13 points in C3 where it accelerates. Speeds average through both fields to 782.0 Km/sec at PA 325 degrees. Acceleration of 16.25 m/sec^s. SDO/AIA 193 shows activated filament material beginning 16:33 UT. Eruption begins approximately 22:57 - 05:018 UT on disk with dimming along north/south filament channel center located [N33, W28] along with post arcading. A flare is triggered from AR 11283 at 07:24 UT from the adjacent filament to it's east. STEREO EUVI A beacon data shows a lift-off 00:25-05:05 UT on NE limb. A data gap of 22:25-00:25 misses the beginning of the event. COR2 B beginning 03:35 UT, a large loop over it's NW limb. Preliminary time/height measure at 9 pts gives speeds 632.2 km/sec. COR2 A beginning 03:24 UT, large loop over the NE. Preliminary time/height measure at 9 pts gives speeds 646.0 km/sec. This is most probably the cause of the Partial HALO event seen in LASCO. The observation of this event is considered 'GOOD'. This CME is determined a FRONTSIDED event. Images and movies and time/height information for this event is available on the web at: http://umbra.nascom.nasa.gov/lasco/observations/halo/2011/110910a/ Best regards, Kevin Schenk Solar Heliospheric Observatory EIT and LASCO Operations NASA-Goddard Space Flight Center, USA BT