Subject: SOHO/LASCO HALO CME 130522b

UCMEO 93001 30523 1530/
30522 71325 81654 2811/ 280// 333// 41537
30522 61235 81355 47513 11745 1112/
99999

PLAIN

SOHO/LASCO observed a asymmetric HALO CME (B) on May 22, 2013.  Event is
first seen in C2 at 13:25 UT with a bright loop on the West in progress
at first frame with the leading edge at 4.5 Rsun. The front expands with
extensions to a full HALO CME by 13:48 UT. The event continues into the C3
field beginning 13:30 to 16:45 UT leaving the C3 field of view at 30Rsun in
the West hemisphere. A large increase of proton flux is seen in LASCO.  

Time/height measurements were marked to 2 points in C2 with speeds of 1620.2 Km/sec
at position angle 281 degrees. The event is marked to 8 points in C3.  Speeds average
through both fields to 1537.1 Km/sec at PA 281 degrees.  Acceleration xxxx m/sec^2.

SDO/AIA 193A shows a CME elevating over the limb on the West beginning 12:36 UT.
An associated flare of AR 11745 at location [N13, W75] fires 13:03-14:00 UT. A
wave is observed and dimming across the West hemisphere.  A post arcade follows
with arcades along ARs 11747 and 11751 to the South.

STEREO: BEACON Data
COR2 A, 13:24-14:54 UT, a full asymmetric HALO CME with loop starting over the East.  
Preliminary time/height measure gives 1551.2 km/sec velocity at LE. 
EUVI A, 12:35-13:55 UT, a CME begins at 12:35 quickly followed by a  flare of
AR 11745 producing a wave and dimming across the East hemisphere. A post arcade
follows.
COR2 B, 13:24-15:24 UT, an asymmetric HALO CME over the East. Full halo
by 13:54 UT.
Preliminary time/height measure gives 1318.8 km/sec velocity at LE. 
EUVI B, A CME is seen over the East limb beginning at 13:25 UT.

NOAA reports a M5.0 class X-ray flare from AR 11745 13:08/13:32/14:08 UT.
The GOES proton monitor shows a sudden increase of proton flux associated
with this event.  Increases of flux levels >100MeV are seen with levels of
>50 MeV peak above solar storm level conditions.  
   
The observation of this event is considered 'GOOD'. This CME is determined a 
FRONTSIDE 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/2013/130522b/

Best regards,

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

BT