SOHO/LASCO Halo CME 20120831

COMMENTS: Asymmetric HALO CME resulting from an eruptive filament located [S19, E50].
LASCO velocity: 1166.7 km/sec at PA111 degrees. Acceleration: -22.19

Halo Alert: halo-message.20120831

SOHO/LASCO HALO CME 120831

UCMEO 93001 20902 2050/
20831 62000 80006 1111/ 110// 333// 31167
20831 61924 82130 25019 11563 2112/
99999

PLAIN

SOHO/LASCO observed a full asymmetric HALO CME on August 31, 2012. Event is first seen
in C2 beginning 20:002 UT with a bright loop with cavity and core over the SE. The event
expands with extensions to a full halo by 20:48 UT. The event continues into the
C3 field beginning 20:18-00:06 UT out to the edge of field at 30 Rsun in the Southeast.

Time/height measurements were marked at 4 points in C2 with speeds of
1063.1 Km/sec at pa 111 degrees. The event is marked to 9 points in C3.
Speeds average through both fields to 1166.7 Km/sec at PA 111 degrees.
Acceleration -22.19 m/sec^2.

SDO AIA 193 shows activation of a filament at 18:51 UT with location centered at [S19,E50].
A dual ribbon flare event. The filament erupts by 19:24-20:48 UT adjacent to and south of
AR11562 and adjacent to AR11563 along the NE while finishing with bright post arcade.
A flare of AR11563 is triggered and observed beginning 20:18 UT. A dimming and wave are
produced with material spanning the east hemisphere.
SDO AIA 304 shows the eruptive filament, material continues to span the face of the disk
with dimming until 09:30 UT.

STEREO: BEACON data and HR data.
COR2 B, 18:25-22:25 UT Data gap. Asymmetric halo already to edge of FOV in first frame.
ADDITION: 20:24-21:54 UT bright loop with cavity and core. Asymmetric halo by
21:24 UT over the West.
Time-height measurements give 1414.2 km/sec velocity @ 266 degrees at LE.
EUVI B 195, 18:36-22:26 UT data gap. n/a
ADDITION: 18:01-21:21 UT eruptive filament near limb in SW. Event produces a wave
over the disk of west hemisphere and a post arcade.
COR2 A, 16:24-02:24 UT Data gap. n/a
ADDITION: 20:24-21:54 UT symmetric halo with cavity and core/ejecta on the East.
Time-height measurements give 976.7 km/sec velocity @ 94 degrees at LE.
EUVI A 195, 16:35-02:05 UT Data gap. n/a

NOAA reports a long duration C8.1 Xray flare 19:45-20:43-21:51 UT from AR 11563 at location [S25,E59]

The observation of this event is considered 'FAIR'. This CME is determined FRONTSIDED.

Images and movies and time/height information for this event is available on the web at:

http://umbra.nascom.nasa.gov/lasco/observations/halo/2012/120831/

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

STEREO/COR2 BEHIND
SDO/AIA193 DIFF
STEREO/COR2 AHEAD

STEREO/EUVI 304 BEHIND
STEREO/EUVI 195 BEHIND
STEREO/EUVI 304 AHEAD

SDO/AIA 193A
SDO/AIA 304A

Time/Height Velocities and Plots

C2/C3

Click on Links below for additional information.

MPEG Movies

LASCO Software IDL Save Files (.mvi)

Please, send questions and comments to Kevin Schenk

SOHO/LASCO C2 Diff	SOHO/LASCO C3 Diff



STEREO/COR2 BEHIND	SDO/AIA193 DIFF	STEREO/COR2 AHEAD

STEREO/EUVI 304 BEHIND	STEREO/EUVI 195 BEHIND	STEREO/EUVI 304 AHEAD

SDO/AIA 193A	SDO/AIA 304A