SOHO/LASCO Partial HALO CME 110808

UCMEO 93001 10809 1600/
10808 61812 82218 1871/ 075// 223// 41489
10808 61803 81836 46116 11263 1122/
99999

PLAIN

SOHO/LASCO observed a partial HALO CME on August 8, 2011.  Event is
first seen in C2 at 18:12 UT with bright impulsive front over the West.
The event expands with extensions PA 187-75 for a total of 277 degrees wide.
The event continues into the C3 field beginning 18:30 to 22:18 UT at 30 Rsun.

Time/height measurements were marked at 3 points in C2 with speeds of 1888.0 Km/sec
at position angle 277 degrees. The event is marked to 7 points in C3 where it slightly
slows.  Speeds average through both fields to 1489.2 Km/sec at PA 281 degrees, 
acceleration -42.5 m/s^.

SDO/AIA 193 shows a flare of AR 11263 18:03-18:236 UT located at [N16 W61] with wave.
STEREO:
COR2 A, 18:24 UT, in east, wide expanding burst.
Preliminary height/time measure was taken on COR2 beacon data showing 1367.9 km/sec
EUVI 195 A, flare 18:05-18:35 of AR 11263 on disk in East with wave progressing
south and east directions.
NOAA reports a M3.5 xray flare of AR 11263 18:00-18:18 UT.  A small rise of proton
flux in the 10 mev level.

This is most probably the cause of the Partial HALO event seen in LASCO.

   
The observation of this event is considered 'GOOD'. 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/2011/110808/

Best regards,

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

BT