SOHO/LASCO Partial HALO CME 121120

UCMEO 93001 21121 1830/
21120 61212 81956 1181/ 171// 223// 40638
21120 61100 81239 43921 ///// 2212/
99999

PLAIN

SOHO/LASCO observed a partial HALO CME on November 20, 2012.  Event is first seen in
C2 beginning 12:12 UT with a loop over the NW.  The event expands with extensions
PA 118-171 for a total width of 307 degrees wide.  The event continues into the
C3 field beginning 12:54-19:56 UT out to the edge of field at 30 Rsun in the Northwest.

Time/height measurements were marked at 3 points in C2 with speeds of
558.2 Km/sec at pa 333 degrees. The event is marked to 8 points in C3.  
Speeds average through both fields to 637.5 Km/sec at PA 333 degrees.
Acceleration 20.52 m/sec^2. 

SDO AIA 193 shows an eruptive filament West of ARs 11616/11619 11:00-12:39 UT
located [N21,W39]. A dimming is seen on disk followed by post arcade.  AIA
304A shows ribbon flaring of the area West of the ARs.

STEREO: BEACON Data
COR2 A,  11:54 UT, a partial halo with cavity and core expands in the East hemisphere.
Preliminary time/height measure gives 814.0 km/sec velocity at LE.
EUVI A 195, n/a
COR2 B, in progress at 13:25 UT, expanding loop over the Northwest hemisphere.
EUVI B 195, n/a

The observation of this event is considered 'GOOD'. 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/2012/121120/

Best regards,

Kevin Schenk
Solar Heliospheric Observatory
EIT and LASCO Operations
NASA-Goddard Space Flight Center, USA

BT