Subject: SOHO/LASCO HALO CME 130517

UCMEO 93001 30317 1840/
30517 60912 81319 0611/ 060// 333// 41436
30517 60844 80924 13712 11748 1112/
99999

PLAIN

SOHO/LASCO observed an asymmetric HALO CME on May 17, 2013.  Event is first
seen in C2 at 09:12 UT as a bright loop over the East.  The event expands with
extensions to a full halo by 09:48 UT. The event continues into the C3 field
beginning 09:30 to 13:19 UT leaving the C3 field of view at 30Rsun. 

Time/height measurements were marked to 2 points in C2 with speeds of 1492.3 Km/sec
at position angle 62 degrees. The event is marked to 10 points in C3.  Speeds average
through both fields to 1436.1 Km/sec at PA 61 degrees.  Acceleration -24.23 m/sec^2.


SDO/AIA 193/211/304A shows a flare of AR 11748 at location [N12, E37] beginning 
08:44-09:24 UT.  The flare produces a dimming and a wave over the East and
North hemispheres. AIA 304 shows brightening/flaring of an area East of
and adjacent to AR 11748 at location [N12, E57] near time of the flare.  

STEREO: BEACON Data
COR2 B, 09:24-10:54 UT expanding partial halo CME over the West.
Preliminary time/height measure gives 1426.9 km/sec velocity at LE. 
EUVI B, 08:45-09:25 UT CME over West limb with wave traveling along limb. 
COR2 A, 08:39-11:24 UT data gap. In progress at first frame, expanding halo
at 11.5 Rsun.
EUVI A,  n/a.

NOAA reports a M3.2 Xray flare 08:42/08:57/09:19 UT from AR 11748
at location [N12, E37]   

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/2013/130517/

Best regards,

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

BT