Halo CME Mail

Date: Mon, 5 Nov 2001 14:22

From: Gareth Lawrence

Subject: Full Halo CME on 2001/11/04


Status: O

UCMEO 93001 11105 1900/
11104 61635 92003 0001/ 360// 233// 51620
11104 61603 81657 41806 09684 1//1/
99999
 
PLAIN
 
BT


LASCO observed a full halo CME on 2001/11/04. The event was 
first observed in C2 at 16:35 UT as a very fast, bright 
loop front over the W limb; by 16:50 UT the C2 occulting disk 
was surrounded. The front first appeared in C3 at 16:45 UT 
with full coverage of the C3 occultor by 17:00 UT. The plane 
of sky speed of the front was measured as 1620 km/s at PA 251
(SW) with discernible acceleration through both coronagraphs' 
fields of view. 

The CME was most probably associated with an X1.0 X-ray flare in 
AR9684 between 16:03 and 16:57 UT with peak emission at 16:20 UT. 
SEC places the flare at S17W20. EIT was in bakeout mode at the 
time and therefore no EUV observations are available from SOHO.
Please note that the third line of the UCMEO code above has been 
completed using GOES X-ray data from SEC's web pages. Note also 
that a proton storm was also observed in association with this 
event and that the later C3 images are particularly degraded.

Images and movies of this event are available at: 
 
ftp://ares.nrl.navy.mil/pub/lasco/halo/20011104

In addition to this large event, LASCO observed another full halo 
CME and a wide partial halo CME. Reports for both of these CMEs
are being prepared, but since they were both substantially slower
and both occured no more than fifteen hours before this main event, 
it seem likely that a single complex ejecta will be encountered 
at 1 AU rather than several distinct events.

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       |
| Building 26, Room G-1,                         +1-301-286-3447       |
| Greenbelt, MD 20771.                   Fax:    +1-301-286-0264       |
+