Subject: SOHO/LASCO HALO CME 130501 BACKSIDED

UCMEO 93001 30501 1800/
30501 60248 81030 0712/ 070// 233// 40728
30501 60215 80315 ///// ///// 1112/
99999

PLAIN

SOHO/LASCO observed a HALO CME on May 01, 2013.  Event is first seen in
C2 at 02:48 UT as a bright loop on the East limb. The front expands with
extensions to a full HALO CME by 04:00 UT. The event continues into the C3
field beginning 03:18 to 10:30 UT leaving the C3 field of view at 30Rsun in
the East hemisphere.  

Time/height measurements were marked to 4 points in C2 with speeds of 825.5 Km/sec
at position angle 71 degrees. The event is marked to 11 points in C3.  Speeds average
through both fields to 728.7 Km/sec at PA 71 degrees.  Acceleration -25.70 m/sec^2.

SDO/AIA 193/304 show a CME from behind the East limb 02:33-03:12 UT.

STEREO: BEACON Data
COR2 B, 03:24-06:39 UT, a full HALO CME with loop starting over the West.  
Preliminary time/height measure gives 511.2 km/sec velocity at LE. 
EUVI B, 02:15-03:15 UT, a flare of an AR on disk in the NW quadrant at
location [N17, E105].  The flare produces a wave and dimming  and post arcade.

COR2 A, 00:54-03:24 UT data gap. Asymmetric HALO CME with core over the West.
Preliminary time/height measure gives 934.2 km/sec velocity at LE. 
EUVI A, 00:00-03:15 UT data gap. n/a

   
The observation of this event is considered 'GOOD'. This CME is determined a BACKSIDED 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/2013/130501/

Best regards,

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

BT