Subject: SOHO/LASCO HALO CME 140312 BACKSIDED

UCMEO 93001 40313 1230/
40312 61436 82130 0522/ 051// 123// 40933
40312 61405 81526 ///// ///// 1112/
99999

PLAIN

SOHO/LASCO observed a HALO CME on March 12, 2014. The event is
first seen in C2 beginning 14:36 UT with a loop over the Northeast.
The event expands with extensions to a full asymmetric halo CME
by 15:12 UT.  The event continues into the C3 field beginning
15:06-21:30 UT where it leaves the C3 field at 30Rsun. 

Time/height measurements were marked at 3 points in C2 with speeds of
1109.3 Km/sec at PA 52 degrees. The event is marked to 9 points in C3.  
Speeds average through both fields to 933.3 Km/sec at PA 52 degrees.
Acceleration -48.12 m/sec^2. 


STEREO: BEACON data
COR2 B,  14:55-17:25 UT at last frame. Asymmetric halo over the North.
Preliminary time/height measure gives 939.2 km/sec velocity at LE.
EUVI B 195, 14:06-15:26 UT flare of AR near disk center at approximate
location [N14, E158]. Data shows a dimming and wave with post arcade.  
COR2 A, 14:39-15:39 UT at last frame, expanding loop over the West.
Preliminary time/height measure gives 1250.7 km/sec velocity at LE.
EUVI A 195, 14:05-15:05 UT, flare on disk in the NW quadrant with
a dimming and wave.


The observation of this event is considered 'GOOD'. This CME is determined BACKSIDED.

Images and movies and time/height information for this event is available on the web at:

http://umbra.nascom.nasa.gov/lasco/observations/halo/2014/140312/

Best regards,

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

BT