SOHO/LASCO Halo CME 20130522b

COMMENTS: Asymmetric HALO CME resulting from a M5.0 class X-ray flare of AR 11745 located [N13, W75]
                          LASCO velocity: 1537.1 km/sec at PA281 degrees. Acceleration:   xxxx
                          Proton flux seen in LASCO images. SEP proton increase above solar storm levels.

Halo Alert: halo-message.20130522b

Subject: SOHO/LASCO HALO CME 130522b

UCMEO 93001 30523 1530/
30522 71325 81654 2811/ 280// 333// 41537
30522 61235 81355 47513 11745 1112/
99999

PLAIN

SOHO/LASCO observed a asymmetric HALO CME (B) on May 22, 2013. Event is
first seen in C2 at 13:25 UT with a bright loop on the West in progress
at first frame with the leading edge at 4.5 Rsun. The front expands with
extensions to a full HALO CME by 13:48 UT. The event continues into the C3
field beginning 13:30 to 16:45 UT leaving the C3 field of view at 30Rsun in
the West hemisphere. A large increase of proton flux is seen in LASCO.

Time/height measurements were marked to 2 points in C2 with speeds of 1620.2 Km/sec
at position angle 281 degrees. The event is marked to 8 points in C3. Speeds average
through both fields to 1537.1 Km/sec at PA 281 degrees. Acceleration xxxx m/sec^2.

SDO/AIA 193A shows a CME elevating over the limb on the West beginning 12:36 UT.
An associated flare of AR 11745 at location [N13, W75] fires 13:03-14:00 UT. A
wave is observed and dimming across the West hemisphere. A post arcade follows
with arcades along ARs 11747 and 11751 to the South.

STEREO: BEACON Data
COR2 A, 13:24-14:54 UT, a full asymmetric HALO CME with loop starting over the East.
Preliminary time/height measure gives 1551.2 km/sec velocity at LE.
EUVI A, 12:35-13:55 UT, a CME begins at 12:35 quickly followed by a flare of
AR 11745 producing a wave and dimming across the East hemisphere. A post arcade
follows.
COR2 B, 13:24-15:24 UT, an asymmetric HALO CME over the East. Full halo
by 13:54 UT.
Preliminary time/height measure gives 1318.8 km/sec velocity at LE.
EUVI B, A CME is seen over the East limb beginning at 13:25 UT.

NOAA reports a M5.0 class X-ray flare from AR 11745 13:08/13:32/14:08 UT.
The GOES proton monitor shows a sudden increase of proton flux associated
with this event. Increases of flux levels >100MeV are seen with levels of
>50 MeV peak above solar storm level conditions.

The observation of this event is considered 'GOOD'. This CME is determined a
FRONTSIDE 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/2013/130522b/

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 304A
STEREO/EUVI AHEAD
STEREO/EUVI AHEAD