SOHO/LASCO HALO CME 130305 BACKSIDED

UCMEO 93001 30307 1630/
30305 60336 80818 0902/ 089// 133// 31049
30305 60312 80409 ///// ///// 1112/
99999

PLAIN

SOHO/LASCO observed a HALO CME on March 05, 2013.  Event is first seen in
C2 beginning 03:36 UT with a bright loop over the East.  The event expands
to a full asymmetric HALO CME by 04:12 UT.  The event continues into the C3 field
beginning 03:54-08:18 UT where it leaves the field of view in the East.

Time/height measurements were marked at 4 points in C2 with speeds of
888.5 Km/sec at PA 90 degrees. The event is marked to 14 points in C3.  
Speeds average through both fields to 1048.7 Km/sec at PA 90 degrees.
Acceleration 09.19 m/sec^2. 

SDO AIA 193 shows backside emission 03:12-04:09 UT in difference images.
Material is seen along the East limb and above the North pole. 

STEREO: BEACON data
COR2 B, 02:25-04:25 UT data gap.  Full symmetric halo in progress at first
frame. Increased proton emission (SEP).
Preliminary time/height measure gives 1081.5 km/sec velocity at LE.
EUVI B 195, 02:26-03:46 UT eclipse outage.  Bright flare of AR near disk
center in progress at first frame at location [N13, E141].  The flare
produces a dimming and a wave which spans the disk in EUVI and a post arcade.
COR2 A, 01:39-05:24 UT data gap. Asymmetric HALO at the edge of field at 
first frame.
EUVI A 195, 01:45-05:35 UT data gap. n/a

The observation of this event is considered 'FAIR'. This CME is determined BACKSIDED.
The vast expansion of the wave of the CME does produce minimal emission which
is seen on disk along the East limb.
 
Images and movies and time/height information for this event is available on the web at:

http://umbra.nascom.nasa.gov/lasco/observations/halo/2013/130305/

Best regards,

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

BT