Halo CME Mail

Date: Fri, 19 Oct 2001 11:31

From: Gareth Lawrence

Subject: Full Halo CME on 2001/10/19

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UCMEO 93001 11019 1530/
11019 60127 91118 0001/ 360// 223// 30468
11019 70113 90148 41816 09661 1112/
99999

PLAIN

BT

LASCO and EIT observed a full halo CME on 2001/10/19. The
event was first observed in C2 at 01:27 UT as a bright
loop front over the W limb; by 02:06 UT the C2 occulting disk
was surrounded. The front first appeared in C3 at 02:18 UT
with full coverage of the C3 occultor by 03:18 UT. The plane
of sky speed of the front was measured as 468 km/s at PA 321
(NW) with slight deceleration through the coronagraphs'
fields of view.

The CME was most probably associated with an X1.6 X-ray flare in
AR9661 between 00:47 and 01:13 UT with peak emission at 01:05.
EIT data for this event is poor since it occurred during the
01 UT synoptic data. The flare is first seen in the 01:13 UT
195 Angstrom inmage from the synoptics, but it is not easy to
say whether peak emission occurs at this time or in the
subsequent regular image at 01:25 UT, since the two images are
not normalised the same way at this time. The previous image,
taken at 00:48 UT, shows no activity. Bright post-CME loops are
visible from 01:48 UT. SEC places the flare at N16W18. An EIT
wave and dimming were observed in association with this event.

Images and movies of this event are available at:

ftp://ares.nrl.navy.mil/pub/lasco/halo/20011019

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       |
++