SOHO/LASCO HALO CME 121121 UCMEO 93001 21124 1540/ 21121 61600 80230 1381/ 137// 323// 30672 21121 61512 81548 10108 11618 1122/ 99999 PLAIN SOHO/LASCO observed a full symmetric HALO CME on November 21, 2012. Event is first seen in C2 beginning 16:00 UT with a faint loop with over the South pole. The event expands to a full halo by 16:36 UT. The event continues into the C3 field beginning 16:30-02:30 UT out to the edge of field at 30 Rsun in the Southeast. Time/height measurements were marked at 6 points in C2 with speeds of 655.3 Km/sec at pa 138 degrees. The event is marked to 10 points in C3. Speeds average through both fields to 672.1 Km/sec at PA 138 degrees. Acceleration -08.30 m/sec^2. SDO AIA 193 shows a flare of AR 11618 at location [N08,E01] 15:12-15:48 UT. This flare produces an expanding wave. STEREO: BEACON data COR2 B, 16:25 UT in first frame, loop over the West. Only 1 frame before data gap till 00:40 UT. EUVI B 195, n/a COR2 A, 14:54-20:24 UT Data gap. n/a EUVI A 195, n/a NOAA reports a M3.5 Xray flare 15:10-15:30-15:38 UT from AR 11618. The observation of this event is considered 'FAIR'. This CME is determined FRONTSIDED. Images and movies and time/height information for this event is available on the web at: http://umbra.nascom.nasa.gov/lasco/observations/halo/2012/121121/ Best regards, Kevin Schenk Solar Heliospheric Observatory EIT and LASCO Operations NASA-Goddard Space Flight Center, USA BT