Subject: SOHO/LASCO HALO CME 130424 BACKSIDED

UCMEO 93001 30424 2000/
30424 60036 80742 0422/ 041// 113// 30653
30423 62326 80036 ///// ///// 1212/
99999

PLAIN

SOHO/LASCO observed a HALO CME on April 24, 2013.  Event is first seen in
C2 at 00:36 UT as a faint loop on the Northeast limb. The front expands with
extensions to a full HALO CME by 01:25 UT. The event continues into the C3
field beginning 01:30 to 07:42 UT leaving the C3 field of view at 30Rsun in
the North hemisphere.  

Time/height measurements were marked to 4 points in C2 with speeds of 644.6 Km/sec
at position angle 42 degrees. The event is marked to 9 points in C3.  Speeds average
through both fields to 653.1 Km/sec at PA 42 degrees.  Acceleration 42.37 m/sec^s.


STEREO: BEACON Data
COR2 B, 00:54-01:39 UT, partial HALO CME expanding over the North and East 
hemispheres. 01:39-05:24 UT data gap while CME is in progress.
Preliminary time/height measure gives 876.6 km/sec velocity at LE. 
EUVI B, 2 associated events: 22:06-23:04 UT,elevated activity of an eruptive
filament channel at approximate location [N30, E160]. There is a dimming associated
with the eruptive which is crossing the AR below.  23:26-00:36 UT the AR flares with
a CME causing a dimming of the area at location [N24, E165] and post arcade.

COR2 A, 20:54-03:39 UT data gap. n/a
EUVI A, 21:15-03:35 UT data gap. n/a

   
The observation of this event is considered 'FAIR'. 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/2013/130424/

Best regards,

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

BT