Subject: SOHO/LASCO HALO CME 100212

UCMEO 93001 00213 0045/
00212 71331 91542 2261/ 165// 123// 20552
00212 ///// ///// 12307 11046 ///// 
99999

PLAIN

SOHO/LASCO C2 observed a partial asymmetric HALO CME already in progress
on February 12, 2010.  First frame observed of the event was 13:31 UT.  Material
spanned 299 degrees wide.  The majority of the event was in the NE at approximately 
41 degrees.  The LE had already left the C2 field of view.  No velocity measurements 
could be properly taken in C2.

C3 showed the event already in progress in its first frame at 13:42.  The LE at 47 degrees
was already at 10.9 Rsun.  We measured at 4 points out to 17.8 Rsun for a very rough
calculation of 552.2 Km/sec at PA 41 degrees on the last image before going into
a DSN gap period.

EIT and LASCO data was not recorded during a loss of DSN coverage from 
Feb 12 2010 01:35 - 13:00 UT.  We have no EIT data for this event.

GOES shows a M8.3 xray flare at 11:19-11:28 UT claiming AR 11046.  
STEREO B EUVI shows a flare of AR 11046 at 11:25 UT.
This flare is most probably associated with the CME observed in the LASCO fields.

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

http://umbra.nascom.nasa.gov/lasco/observations/halo/2010/100212/

Best regards,

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

BT