Subject: SOHO/LASCO HALO CME 110802

UCMEO 93001 10802 1700/
10802 60636 91506 2751/ 274// 323// 40819
10802 60539 80657 41514 11261 1222/
99999

PLAIN

SOHO/LASCO observed a HALO CME on August 2, 2011.  Event is first seen in
C2 at 06:36 UT as an impulsive loop over the West centered at PA 283
degrees. The cme propagates with extensions to a full hallo cme.
The event continues into the C3 field beginning 07:06 to 15:06 UT out to
30 Rsun.

Time/height measurements were marked at 4 points in C2 with speeds of 736.7 Km/sec
at position angle 279 degrees. The event is marked to 8 points in C3 where it
accelerates.  Speeds average through both fields to 819.3 Km/sec at PA 279 degrees.
Acceleration of -0.07 m/sec^s.

SDO/AIA 193 shows a flaring of AR 11261 05:39-06:57 UT located near disk center
at [N14 W115].  The flare is followed by a dimming with wave spreading across
the west hemisphere. 
STEREO COR2 A, beginning 06:24 UT, a large loop with cavity and core over the East.
Preliminary height/time measure was taken on the beacon data showing 1014.9 km/sec
cme speeds out to 12 Rsun.
NOAA reports a M1.4 long duration xray flare of AR 11261 05:19-06:48 UT

This is most probably the cause of the FULL 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/2011/110802/

Best regards,

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

BT