Halo CME Mail

Date: Mon, 21 Apr 2003 15:18

From: Gareth Lawrence

Subject: Partial Halo CME on 2003/04/21, probably frontsided

Status: O

UCMEO 93001 30421 1915/
30421 61336 91842 2181/ 015// 213// 30992
///// ///// ///// ///// ///// /////

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: 

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.

| Gareth Lawrence,                   E-mail:grl@kreutz.nascom.nasa.gov |
| SOHO-LASCO Operations Scientist,				       |
| CUA, Mail Code 682.3,                                                |
| NASA Goddard Space Flight Center,      Phone:  +1-301-286-2941       |
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