SOHO/LASCO HALO CME 120719

UCMEO 93001 20719 1520/
20719 60524 80824 2531/ 252// 333// 41681
20719 60427 80654 39217 11520 1112/
99999

PLAIN

SOHO/LASCO observed a HALO CME on July 19, 2012.  Event is first seen in C2 at
05:24 UT as a bright loop with cavity and core.  The event develops with extensions
to a full asymmetric HALO (west) by 06:36 UT. The event continues into the C3 field
beginning 05:42-08:42 UT out to the edge of field at 30 Rsun in the West.
Increased proton flux is seen in the white light images.

Time/height measurements were marked at 3 points in C2 with speeds of
1449.3 km/sec at position angle 253 degrees. The event is marked to
9 points in C3.  Speeds average through both fields to 1680.6 Km/sec
at PA 253 degrees. Acceleration of -15.15 m/sec^2. 

SDO AIA 193 shows a flare on the limb in the west 04:27-06:54 UT.  The flare
produces a dimming and a wave on disk across the west hemisphere.

STEREO: BEACON data
COR2 A,  05:39 UT, a bright loop expands to an asymmetric halo (east). 
Preliminary time/height measure gives 1174.4 km/sec velocity at LE.
EUVI A 195, 04:35-06:25 UT a flare of AR 11520 on disk in SE located [S17,W92].
A wave is produced spanning most of the face.
COR2 B, 05:54 UT cme expands to a symmetric halo.
Preliminary time/height measure gives 1150.4 km/sec velocity at LE.
EUVI B 195, n/a

NOAA reports an M7.7 Xray flare 04:17-05:58-06:56 UT from AR 11520 at location [S17,W91]
GOES13 shows an instant increase in proton flux with particles >100MeV.  Particles
in the 10MeV range remain above storm levels.

The observation of this event is considered 'GOOD'. This CME is determined a LIMB event.
Material in transfered across the face of the disk.

Images and movies and time/height information for this event is available on the web at:

http://umbra.nascom.nasa.gov/lasco/observations/halo/2012/120719/

Best regards,

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

BT