Date: Wed, 7 Jul 2004 11:17
From: Guillermo Stenborg
Subject: 'Full' Halo CME on 2004/07/06, most probably backsided
UCMEO 93001 40707 1520/
40706 62006 80942 0002/ 360// 123// 30971
///// ///// ///// ///// ///// /////
99999
PLAIN
BT
LASCO observed an asymmetric 'full' halo CME on 2004/07/06.
The event was first observed in C2 at 20:06 UT as a diffuse
front above the SE Limb. By 20:30 UT the C2 occultor is
completely covered, though the part of the front above the
NW Limb is fainter than the rest. The event is first seen in
C3 at 20:42 UT spanning from the E Limb up to the S Pole.
For reference, the mean plane-of-sky speed at several PA
is given below (based only in C3 data):
PA 031: 533 km/s
PA 092: 914 km/s
PA 122: 930 km/s
PA 200: 971 km/s
in all cases showing an slight deceleration.
GOES records no significant X-ray activity by the time.
Likewise, EIT Fe XII images show no significant activity
on the disk. On the other hand, EIT Fe XII running difference
images show signatures of a big CME originated in the far
side of the Sun developing mainly toward SE between 20:00
and 21:24 UT. Therefore, the event can be catalogued as a
'full' HALO CME, most probably backsided.
Movies and images of the event will shortly be available at:
ftp://ares.nrl.navy.mil/pub/lasco/halo/20040706
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
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