Subject: SOHO/LASCO HALO CME 131011 BACKSIDED

UCMEO 93001 31014 1930/
31011 60742 81342 0841/ 083// 333// 41175
31011 60706 80846 19620 11869 1112/
99999

PLAIN

SOHO/LASCO observed an asymmetric HALO CME on October 11, 2013.  Event is
first seen in C2 beginning 07:24 UT with a bright loop over the Northeast.
The event expands with extensions to a full HALO with cavity and core by
08:48 UT.  The event continues into the C3 field beginning 07:42-13:42 UT
leaving the C3 field at 30Rsun in the East. 

Time/height measurements were marked at 3 points in C2 with speeds of
1250.9 Km/sec at PA 82 degrees. The event is marked to 6 points in C3.  
Speeds average through both fields to 1175.2 Km/sec at PA 84 degrees.
Acceleration -68.53 m/sec^2. 

SDO/AIA 193A shows a flare over the East limb 07:09-07:39 UT at [N20]
producing a wave along the limb over the East.

STEREO: BEACON data
COR2 B,  07:55-10:55 UT asymmetric halo over the Northwest. Increased
proton flux emission seen in the field of view.
Preliminary time/height measure gives 1106.8 km/sec velocity at LE.
EUVI B 195, 07:06-08:46 UT flare of active region 11869 on disk
in the NW quadrant at location [N20, E096].
The event produces a dimming and wave followed by a post arcade.
COR2 A, 07:39-10:24 UT, expanding asymmetric HALO over the West. 
Preliminary time/height measure gives 958.6 km/sec velocity at LE.
EUVI A 195, n/a

GOES shows an M1.5 Xray flare 07:01/07:25/07:45 UT.  This flare is associated
to the event observed in LASCO.

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/2013/131011/

Best regards,

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

BT