Subject: SOHO/LASCO Partial HALO CME 120126

UCMEO 93001 20126 1930/
20126 60436 81006 1981/ 106// 333// 31243
20126 60348 80603 46245 11402 2212/
99999

PLAIN

SOHO/LASCO observed a Partial HALO CME on January 26, 2012.  Event is first seen in
C2 at 04:36 UT as a bright loop front on the north west centered at pa 325.
The event develops a defined loop with cavity and core. The front expands
with extensions PA 198-106 degrees for total coverage of 268 degrees.
The event continues into the C3 field beginning 05:15 to 10:06 UT out to the edge of
view at 30 Rsun in the NW.

Time/height measurements were marked to 7 points in C2 with speeds of 930.4 Km/sec
at position angle 323 degrees. The event is marked to 10 points in C3 where it
accelerates.  Speeds average through both fields to 1242.7 Km/sec at
PA 322 degrees.  Acceleration 83.37 m/sec^s.


SDO/AIA shows a CME/eruption from an area centered at [N45,W62] above AR 11402 in
the NW quadrant currently located at [N26, W70] beginning 03:48-06:03 UT,
finishing with flaring between these 2 regions at 05:03 UT and bright post loop arcade.


STEREO: Beacon data
COR2 B,  02:55-08:25 UT data gap. 
EUVI B, 02:56-08:26 UT data gap.
COR2 A, 21:54-05:24 UT data gap.  In progress, burst, 1st frame at 4.9 Rsun.  NE projection
expands to full halo with extensions.
Preliminary time/height measure gives 1623.1 km/sec velocity at LE.
EUVI A, 22:05-05:55 UT data gap. In progress, looping arcade over AR in NE.

   
The observation of this event is considered 'FAIR'. 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/2012/120126/

Best regards,

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

BT