Subject: SOHO/LASCO Partial HALO CME 100524

UCMEO 93001 00524 2245/
00524 61406 92142 1241/ 009// 113// 20397
00524 61124 81736 43115 ///// 2212/
99999

PLAIN

SOHO/LASCO observed a partial HALO CME (type P) on May 24, 2010.  Event began in C2 at 14:06 UT
as an asymmetric loop front with core centered over PA 269 degrees. The CME consisted of 3
components in C2; main loop with core in SW at PA 261, the expanding loop to the south, and a 
burst in the NNW at PA 333, expanding at approximately the same acceleration. 
Material is seen from PA 124 - 9 degrees for a total coverage of 245 degrees wide.
The event continues into the C3 field beginning at 15:42 UT.   The CME tracked through the 
field to the last frame while in progress at 21:42 UT to 17.9 Rsun.

Time/height measurements were marked to 16 points and calculated to velocities of this
event averaging 397.4. Km/sec at position angle 261 degrees.  This event was accelerating as
it entered the C3 field, 347 km/sec through C2 to 420 km/sec through C3.  

The event was first seen in EIT beginning at 11:24-17:36 UT with a filament eruption in the North
West centered at [N15 W31].  A lift of beggins with a dimming at the south of the channel while
triggering what looked to be a dual ribbon flaring between the channel on its east, finishing
with a long duration post arcading.

The eruption seen in EIT confirms a FRONTSIDED HALO event.

EIT and LASCO images, movies and time/height information for this event is available on the web at:

http://umbra.nascom.nasa.gov/lasco/observations/halo/2010/100524

Best regards,

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

BT