Subject: SOHO/LASCO HALO CME 120928b BACKSIDED

UCMEO 93001 21001 2230/
20928 61036 91654 0852/ 084// 313// 40609
20928 60955 81055 ///// ///// 1112/
99999

PLAIN

SOHO/LASCO observed a second (2) HALO CME on September 28, 2012.  Event is first
seen in C2 at 10:36 UT as a faint loop over the Southwest limb which
produced a symmetric halo by the send frame at 10:48 UT.  The event continues into
the C3 field beginning 10:54 to 16:54 UT where the event dissipates at 21.5 Rsun.

Time/height measurements were marked to 5 points in C2 with speeds 
of 673.7 Km/sec at position angle 85 degrees. The event is marked to 6 points 
in C3. Speeds average through both fields to 608.7 Km/sec at PA 85 degrees.  
Acceleration n/a.

SDO/AIA : n/a

STEREO: BEACON  Data
COR2 B, In progress 11:25-12:40 UT, burst expands over East.  Develops a partial halo.
Preliminary time/height measure gives 1046.6 km/sec velocity at LE.
EUVI B, 09:56-10:56 UT. Bright flare from AR on SE limb. Event produces a wave.
COR2 A, 10:39-12:54 UT, expanding loop with cavity and core over West hemisphere.
Preliminary time/height measure gives 917.1 km/sec velocity at LE.
EUVI A, 09:55-10:55 UT. Flare with a wave and dimming from region located on disk
at [S21, W167].

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/2012/120928b/

Best regards,

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

BT