Subject: SOHO/LASCO HALO CME 100807

UCMEO 93001 00809 1635/
00807 61836 80054 0901/ 089// 123// 40854
00807 61756 81916 13714 11093 1122/
99999

PLAIN

SOHO/LASCO observed a full asymmetric HALO CME (type A) on August 7, 2010.  Event is first seen in 
C2 at 18:36 UT as a bright loop leading edge over the east limb at PA 90 degrees. The event 
quickly developed to a full HALO with material at all positions by 19:24 UT.  The event 
continues into the C3 field first frame of 18:54 and tracked to 00:54 UT to 24 Rsun.

Time/height measurements were marked to 3 points in C2 with speeds of 1059 km/sec, the event
decelerates in C3, marked at 18 points and calculated to velocities averaging thru both fields
to 853.6 Km/sec at position angle 91 degrees.    

STEREO Behind EUVI 195A beacon data nicely shows AR 11093 in the West field with a bright flare/
ribbon event beginning at 17:56-19:16 UT followed by arcade.
NOAA reports a M1.0 Xray flare of AR 11093 beginning at 17:55 UT, located at [N14, E37]. This is
most probably the cause of the 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/2010/100807/

Best regards,

Kevin Schenk
SOHO Mission
EIT and LASCO Operations
NASA-Goddard Space Flight Center, USA

BT