Halo CME Mail

Date: Tue, 13 Jul 2004 13:31

From: Guillermo Stenborg

Subject: Another 'full' halo CME on 2004/07/13, frontsided



UCMEO 93001 40713 1730/
40713 60908 91718 0001/ 360// 213// 20571
40713 60840 80855 45114 10646 1112/
99999
 
PLAIN
 
BT 

LASCO & EIT observed a couple of at least partly Earth-directed 
events on 2004/07/13, which showed up in the LASCO coronagraphs 
FOV as rather faint 'full' Halo CMEs. This report refers to the 
SECOND of them.

The second event was first observed in C2 at 09:08 UT just above 
the WNW Limb, developing in the trailing material of previous
reported event. As for the other event, during its development
in C2, 2 parts are distinguishable: i) a bright ragged loop 
front, and ii) a fainter and diffuse front to N and ahead of 
the other front. By 10:30 UT the faint extensions seem to cover 
the C2 occultor, though due to their faintness, they are 
difficult to follow after a couple of frames. The halo extensions 
are, like with previous event, barely visible in C3.  

The mean plane-of-sky speed for the event as measured at the LE
of the ragged front [i)], at PA ~278, was ~571 km/sec (based on 
C3 data).

In this case, the C2 event was most probably associated with 
the M5.4 X-ray flare occurred above NOAA AR 0646 (by the time
at N14W51) between 08:40 - 08:55 UT with peak emission at 
08:48 UT. EIT Fe XII running difference images show signatures of 
the event between approximately 08:48 and 10:14 UT, showing
the brightening (flare) peaking at 08:48 UT. Moreover, like in
previous event, a large intensity disturbance traveling across
the disk mainly toward NE is evident (wave) and also toward NW 
(CME signature). This event has therefore been determined as,
at least most likely, partly Earth-directed. 

Images and movies will shortly be made available at (for both, 
the event reported in this message and previous reported event):  

ftp://ares.nrl.navy.mil/pub/lasco/halo/20040713

Best wishes,
	Guillermo Stenborg

++
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
++