SOHO/LASCO Halo CME 20130515

COMMENTS: Asymmetric HALO CME resulting from a X1.2 class X-ray flare of AR 11748 located [N12, E64]
LASCO velocity: 1511.2 km/sec at PA70 degrees. Acceleration: 42.46

Halo Alert: halo-message.20130515

Subject: SOHO/LASCO HALO CME 130515

UCMEO 93001 30515 1740/
30515 60148 80518 0701/ 069// 333// 41511
30515 60124 80155 16412 11748 1112/
99999

PLAIN

SOHO/LASCO observed an asymmetric HALO CME on May 15, 2013. Event is first seen in
C2 at 01:48 UT as a bright loop with cavity and core on the East. The event expands
with extensions to a full HALO CME by 02:48 UT. The event continues into the C3
field beginning 02:06 to 05:18 UT leaving the C3 field of view at 30Rsun.

Time/height measurements were marked to 3 points in C2 with speeds of 1471.9 Km/sec
at position angle 70 degrees. The event is marked to 7 points in C3. Speeds average
through both fields to 1511.2 Km/sec at PA 70 degrees. Acceleration 42.46 m/sec^s.

SDO/AIA 193/211/304 show a flare of AR 11748 at location [N12, E64] beginning
01:24-02:12 UT producing a faint dimming in the Northeast and North direction
and a wave over the East hemisphere.

STEREO: BEACON Data
COR2 B, 01:54-03:39 UT expanding asymmetric HALO CME (West).
Preliminary time/height measure gives 1940.0 km/sec velocity at LE.
EUVI B, 00:25-01:55 UT flare of AR 11748 crossing the limb in the NW.
COR2 A, 20:54-02:55 UT data gap. At first frame, event in progress to
9.7Rsun, symmetric HALO CME.
EUVI A, 20:55-02:55 UT data gap. n/a

NOAA reports a X1.2 Xray flare 01:25/01:48/01:58 UT from AR 11748
at location [N11, E64] with increasing proton flux of 10 and 50 MeV with
>10MeV above storm levels at the time of this alert.

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/2013/130515/

Best regards,

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

BT

SOHO/LASCO C2 Diff
SOHO/LASCO C3 Diff
SDO/AIA 193A

STEREO/COR2 BEHIND
SDO/AIA 193A Diff
STEREO/COR2 AHEAD

SDO/AIA 211A
STEREO/EUVI BEHIND
STEREO/EUVI BEHIND