Halo CME Mail

Date: Fri, 5 Nov 2004 07:39

From: Guillermo Stenborg

Subject: Partial Halo CME on 2004/11/04, frontsided



UCMEO 93001 41105 1240/
41104 60954 82142 1801/ 100// 123// 10635
41104 60845 81004 12809 10696 1122/
99999
 
PLAIN
 
BT 

LASCO/EIT observed a couple of frontsided events on 2004/11/04.
The one that was first seen in C2 at 09:54 UT will be reported in this 
message. Shortly afterward, the other one (first seen in C2 at 23:30 UT)
will be reported in a following alert.

The event that concerns us in this report was first observed in C2 
at 09:54 UT above the NE Limb, as a bright loop front with a 
faint and diffuse extension all above the NW, W, and NW Limbs. 
The event was first seen on C3 at 10:42 UT above the NE Limb, developing 
mainly toward NE. The extensions continue very clear all around the N
Pole, NW, W, and SW Limbs. Nothing can be distinguished above the SE 
Limb. By 13:42 UT, the event (excess brightness) spans in C3 ~ 280 deg
from PA 180 - 100.The mean plane-of-sky speed of the LE of the front at 
PA 31 was ~ 635 km/sec (based on C3 data) showing practically no 
acceleration.

GOES reported an C6.3 X-ray flare on NOAA AR 10696 (N09E28) between 
08:45 - 10:04 with peak emission at 09:05 UT, most likely asssociated
to the event described above. On the other hand, EIT 195 images
show a brightening on the aforementioned AR at 09:00 UT, with signatures
of a CME developing mainly towards NE. But please note that since around 
07:13 UT excess activity begins to be seen on that AR. GOES reported 
also a C1.0 X-ray flare on NOAA AR 10696 (N09E28) between 07:23 - 07:28 
UT with peak emission at 07:26 UT
 
In summary and based on its appearance in the C3 FOV, the event has 
therefore been determined as a partial halo CME, frontsided.

Movies and images of the event will shortly be made available 
at: 

ftp://ares.nrl.navy.mil/pub/lasco/halo/20041104a


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
++