Subject: SOHO/LASCO HALO CME 131025b

UCMEO 93001 31025 2100/
31025 61512 91706 0941/ 093// 333// 41247
31025 61442 81521 26808 11882 1112/
99999

PLAIN

SOHO/LASCO observed a second (B) HALO CME on October 25, 2013.  This event is
first seen in C2 at 15:12 UT as a bright loop with cavity and core in the East.
The event expands to full asymmetric HALO by 16:12 UT. The event continues
into the C3 field beginning 15:32 to 17:06 UT at last frame before SOHO entered
a gap in DSN contact.

Time/height measurements were marked to 3 points in C2 with speeds of 1476.1 Km/sec
at position angle 92 degrees. The event is marked to 8 points in C3.  Speeds average
through both fields to 1247.0 Km/sec at PA 94 degrees.  Acceleration -61.04 m/sec^2.


SDO/AIA 193A shows a flare from active region 11882 at location [S08, E68]
beginning 14:42-15:21 UT.  A dimming is seen across the East hemisphere and 
a wave is seen propagating across the disk.

STEREO: BEACON Data
COR2 A, a data gap begins at 14:54 UT.  n/a/
EUVI A, n/a.
COR2 B, 15:25-16:25 UT. Loops over the West expands to an asymmetric halo.
A data gap begins at 16:30 UT.
Preliminary time/height measure gives 1270.9 km/sec velocity at LE.
EUVI B, 14:46-15:26 UT, a flare of AR 11882 with a dimming and wave along the
West hemisphere with the wave running along the limb.

NOAA reports a X2.1 Xray flare 14:51/15:03/15:12 UT from AR 11882.

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/2013/131025b/

Best regards,

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

BT