Subject: SOHO/LASCO HALO CME 121108b BACKSIDED

UCMEO 93001 21109 2130/
21108 61100 81654 2512/ 250// 323// 41014
21108 61025 81205 ///// ///// 1112/
99999

PLAIN

SOHO/LASCO observed two HALO CMEs on November 08, 2012. This alert is for
the second event (B). The Event is first seen in C2 at 11:00 UT as a loop
surfacing over the Southwest limb with cavity and core. The event expands
to a full symmetric halo CME by 11:24 UT.  The event continues into the C3
field beginning 11:30 to 16:42 UT leaving the C3 field at 30 Rsun in the West.

Time/height measurements were marked to 4 points in C2 with speeds 
of 939.7 Km/sec at position angle 251 degrees. The event is marked to 10 points 
in C3. Speeds average through both fields to 1013.8 Km/sec at PA 251 degrees.  
Acceleration -18.57 m/sec^2.

SDO/AIA : n/a

STEREO: BEACON DATA
COR2 A, 11:24 UT asymmetric halo with cavity and core in the West .
Preliminary time/height measure gives 1150.1 km/sec velocity at LE.
EUVI A 195, 10:25-12:05 UT a flare is seen producing a dimming and wave.  The
AR is located on disk at [S12, W168].
COR2 B, 11:25 UT asymmetric halo with cavity and core over the east/southeast.
Preliminary time/height measure gives 1422.6 km/sec velocity at LE.
EUVI A 195, shows a flare producing a wave on limb in SE 10:26-11:26 UT.  Post arcade
rises over limb.

The observation of this event is considered 'GOOD'. This CME is determined a BACKSIDED 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/2012/121108b/

Best regards,

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

BT