Subject: SOHO/LASCO Partial HALO CME 100403 

UCMEO 93001 00405 1900/
00403 61033 80842 0441/ 287// 123// 30512
00403 610914 80948 32503 11059 1112/
99999

PLAIN

SOHO/LASCO observed a partial HALO CME (type P) on April 03, 2010.  Event began in C2 at 10:33 UT
as a wide symmetric loop front over the South Pole, centered approximately PA 182 degrees.
Material spanned PA 44 - 273 for a total coverage of 243 degrees over the entire southern hemisphere.
By 11:06 UT a second wave begins over the south with a slow multiloop front.
The event continues into the C3 field beginning at 11:18 UT over the South Pole and measured through
the field as the event ends at approximately 18:42 UT to 21 Rsun.

Time/height measurements were marked to 10 points and calculated to velocities of this
event averaging 512. Km/sec at position angle 192 degrees through C2 and accelerating in C3.

The event was first seen in EIT  09:14-09:48 UT with a flare of AR 11059 then located at [S25W03].
The flare produces a faint EIT wave with South, and Southwestern direction and a post arcade.
By 12:12 UT a dimming along the filament channel south of AR 11059 is seen.  These events in EIT
most possibly pertains to the event seen in LASCO.

GOES reports a long duration class B7.4 xray flare of AR 11059 on April 3, 2010 09:04-09:54 UT.
The events in EIT and Lasco are most probably related to this flare and confirming 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/2010/100403/

Best regards,

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

BT