http://lasco-www.nrl.navy.mil/mail/halo_mail/198.html
Date: Mon, 21 Apr 2003 15:18
From: Gareth Lawrence
Subject: Partial Halo CME on 2003/04/21, probably frontsided
UCMEO 93001 30421 1915/
30421 61336 91842 2181/ 015// 213// 30992
///// ///// ///// ///// ///// /////
99999
PLAIN
BT
LASCO observed a possible partial halo CME on 2003/02/01. The
event was first observed in C2 at 13:36 UT as a ragged loop
front over the NW limb; by 14:00 UT it spanned ~157 deg from
PA 218 - 15. The front first appeared in C3 at 14:18 UT
though the front is extremely faint in C3 images. The mean
plane-of-sky speed for the system was 992 km/s at PA 318,
with no strong indication of acceleration. Only C2 data
were used to measure this speed.
EIT was undergoing a routine CCD bakeout by this time, so
no on-disk EUV data are available. However, GOES recorded
a M2.8 X-ray flare between 12:54 - 13:14 UT with peak
emission at 13:07 UT. The flare was also images by the
SXI soft X-ray imager onboard GOES-12. This event has
therefore been determined most probably frontsided.
Movies and images of this event are available now at:
ftp://ares.nrl.navy.mil/pub/lasco/halo/20030421
and please note that the C3 movie is only partial due
to DSN contact scheduling, and that the front in the NW
is extremely faint in C3 images.
Some people may experience difficulties obtaining the images and
movies at present; this is due to unresolved issues with the
firewall at NRL. Aplogies to those affected; the problem is being
worked on.
Best wishes,
Gareth Lawrence.
Gruß Lutz
