Date: Mon, 13 Sep 2004 09:46
From: Guillermo Stenborg
Subject: 'Full' Halo CME on 2004/09/12, frontsided
UCMEO 93001 40913 1335/
40912 60036 81042 0001/ 360// 323// 31326
40912 60004 80133 14903 10672 1//1/
99999
PLAIN
BT
LASCO observed a 'circular' off-centered 'full' halo CME on
2004/09/12. The event was first observed in C2 at 00:36 UT above
the E Limb developing as a bright loop front. A strong cavity and
inner core can be well distinguished by 01:24 UT. At that time the
LE on E is already above the end of C2 FOV, and fainter loop-like
extensions already cover the C2 occultor, spanning from the N to
the S Pole, all above the W Limb. Much trailing material follows
on E. The event is first seen on C3 at 01:18 UT above the E Limb.
By 02:18 UT the C3 occultor is completely covered, the LE on the
E Limb being at ~ 13 solar radii, while on W the LE is only at
above 5.5 solar radii from disk center. For reference, the mean
plane-of-sky speed for the LE of the outermost feature at various
PA is given below (based on C3 data):
PA 044 : 1150 km/sec
PA 086 : 1262 km/sec
PA 140 : 1326 km/sec
PA 221 : 787 km/sec
PA 296 : 470 km/sec
GOES recorded an M4.8 X-ray flare from the NOAA AR 10672 (N03E49)
between 00:04 - 01:33 UT with peak emission at 00:56 UT. Please
note that SOHO entered a telemetry keyhole on 2004/09/11 that will
last until 2004/10/06. Between 2004/09/10 22:00 UT - 2004/10/03
22:00 UT EIT will be performing the CCD bakeout and therefore no
EIT images will be available during that period.
The event has therefore been determined as an off-centered 'full'
halo CME, most likely frontsided in spite of the temporal correlation
observed with the X-ray event.
Movies and images of the event will shortly be made available at:
ftp://ares.nrl.navy.mil/pub/lasco/halo/20040912
Best wishes,
Guillermo Stenborg
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Dr. Guillermo A. Stenborg
SOHO-LASCO Operations Scientist,
CUA, MC 682.3, Bldg 26, Rm 001, F: +1-301-286-0264
NASA Goddard Space Flight Center,
Greenbelt, MD 20771. P: +1-301-286-2941
e-mail: stenborg@kreutz.nascom.nasa.gov
++