SOHO/LASCO HALO CME 120216 BACKSIDED

UCMEO 93001 20216 2030/
20216 60624 81530 3152/ 314// 113// 30540
20216 60535 90555 ///// ///// 4122/
99999

PLAIN

SOHO/LASCO observed a HALO CME on February 16, 2012.  Event is
first seen in C2 at 06:24 UT with faint material at all positions.
The event progresses, at 06:48 a loop LE shows over the NW limb
and expands.  This appears as an addition of a second related system.
The event continues into the C3 field beginning 07:30-15:30 UT
as it leaves the C3 field at 30 Rsun in the NW.

Time/height measurements were marked at 8 points in C2 with speeds of 500.2 Km/sec
at position angle 315 degrees. The event is marked to 9 points in C3.  Speeds
average through both fields to 540.3 Km/sec at PA 316 degrees. Acceleration of
11.72 m/sec^2. 

SDO AIA: n/a
STEREO: Beacon data
COR2 A, 2/15 22:45-05:24 UT and 05:54-09:24 UT data gaps.  09:24 UT in progress,
CME at 12 Rsun over west hemisphere. 
EUVI A 195, 05:35 UT start of AR in NW cme with wave. Data gap 05:55-09:25 UT
COR2 B, 06:25-10:40 UT expanding loop over the East hemisphere.
Preliminary height/time measure was taken on COR2 B beacon data showing 678.4 km/sec.
EUVI B 195, CME over East limb at 05:46 UT with post loops surfacing.  


The observation of this event is considered 'FAIR'. 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/2012/120216/

Best regards,

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

BT