Halo CME MailHalo CME Mail
Date: Tue, 4 Nov 2003 10:42
From: Gareth Lawrence 
Subject: Full Halo CME on 2003/11/04, backsided




LASCO observed a full halo CME on 2003/11/04. A bright
front was first visible in C2 images at 12:06 UT as a
full halo CME surrounding the entire occulting disk,
then at 12:18 UT as a full halo CME in C3 images.

Analysis of the EIT running difference data clearly 
shows evidence of a backsided event around all regions 
of the solar limb. This suggests a backsided source 
having fairly centrally located origin, which in turn
is consistent with the very symmetric emission seen 
through both the C2 and C3 fields of view. This event
has therefore been determined backsided.

Please note that LASCO also observed a backsided halo 
CME on 2003/11/03, from 09:30 UT. This event was 
characterised by brighter emission to the W, consistent
with a backsided source closer to the W limb. It is
possible that these two recent event share a common 
and active source region presently transiting the 
backsided disk, which could conceivably lead in turn 
to frontsided activity in the near future.

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
++