Halo CME Mail

Date: Thu, 20 Nov 2003 17:41

From: Gareth Lawrence

Subject: 'Full' Halo CME on 2003/11/18, frontsided

Status: O

UCMEO 93001 31120 2100/
31120 60806 91718 0001/ 360// 213// 40547
31120 60736 90812 40803 10501 1112/

NOTE: this message is being resent due to the original being 
      curtailed and sent without a subject

LASCO and EIT observed a 'full' halo CME on 2003/11/20. A  
ragged loop front was seen in C2 at 08:06 UT in the SE and
by 08:26 UT this front had faint extensions surrounding the C2
occultor. From 08:50 UT onwards the event was only clearly
visible spanning ~160 deg from the SE to NW. The bright front
first appeared in C3 images in the SE at 08:42 UT with faint
extension towards the N pole and over the S pole. The mean 
plane-of-sky speed was 547 km/s, measured at PA 253 with no
strong evidence for any acceleration.

The CME was probably associated with a M9.6 X-ray flare which
EIT observed between 07:36 - 08:12 UT, centered N03W08 and
with peak activity at 07:48 UT. Additionally, a filament 
channel to the S of the active region was activated and
subsequently erupted. SEC records the flare between 07:35 - 
07:53 UT from AR 0501. A modest EIT wave and slight dimming 
were observed in association with this event. This event 
has therefore been determined frontsided.

Images and movies will shortly be made available at  


Also, please note a typo in the last halo CME report,
dated 2003/11/18. In the text it stated first that the
flare originated in AR 0501, and later from AR 0498.
Only AR 0501 was associated with this event. Apologies 
for any confusion. 

Best wishes,
        Gareth Lawrence.

+----------PLEASE NOTE NEW EMAIL ADDRESS-----------+
Gareth Lawrence,           grl@grace.nascom.nasa.gov 
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