Subject: SOHO/LASCO HALO CME 120119

UCMEO 93001 20120 1530/
20119 61512 81954 0411/ 040// 333// 41698
20119 61345 81624 12232 11402 1212/
99999

PLAIN

SOHO/LASCO observed a full HALO CME on January 19, 2012.  Event is first seen in
C2 at 15:12 UT as a bright loop over the north east centered at pa 40, LE at 3.5 Rsun.
The impulsive front expands with cavity and core to a full halo by 15:48 UT.
The event continues into the C3 field beginning 15:30 to 19:54 UT out to the edge of
view at 30 Rsun.

Time/height measurements were marked to 4 points in C2 with speeds of 1357.6 Km/sec
at position angle 27 degrees. The event is marked to 12 points in C3 where it
slightly accelerates.  Speeds average through both fields to 1698.1 Km/sec at
PA 28 degrees.  Acceleration 0.81 m/sec^s.


SDO/AIA shows a flare of AR 11402  in the NE quadrant [N32, E22]
beginning 13:45-16:24 UT with a dimming and bright post loop arcade. The
flare triggered a filament adjacent to the AR north to erupt centered at
[N44,E25] with bright ejecta.

NOAA reports a long duration M3.2 Xray flare beginning 13:44-17:50 UT from AR 11402.

STEREO: Beacon data
COR2 B,  14:55-17:525 UT a loop front with cavity and core  expanding over the west. 
Preliminary time/height measure gives 1153.4 km/sec velocity at LE.
EUVI B, 13:56-15:26 UT CME over NW limb with bright post loops.
COR2 A, 14:54-16:54 UT impulsive loop with cavity and core  overtaking cme east.
Preliminary time/height measure gives 1036.5 km/sec velocity at LE.
EUVI A, 11:36-14:05 UT data gap.  CME in progress on limb in NE.

   
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/2012/120119/

Best regards,

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

BT