Halo CME Mail

Date: Wed, 18 Sep 2002 18:57:08 +0000 (GMT)

From: Kevin Schenk

Subject: Partial HALO CME of 2002/09/17

  ------------------------------------------------------------------------

UCMEO 93001 20917 1823/
20917 60754 81618 0951/ 315// 333// 40857
20917 60600 80936 31228 10114 1122/
99999

BT

EIT and LASCO observed a partial HALO CME on 2002/09/17.
The event was first seen in C2 field at 07:54 UT as a wide loop front with
cavity and trailing core.  Material spanning PA 95-315 degrees.  The event
was seen in C3 beginning 08:42 UT and tracked to a distance of 28 Rs by
16:18 UT.  The averaged plane-of-sky speed through both fields is 857
km/sec at PA 218 degrees with slight deceleration through C3.

EIT saw a chain of events which may have all been factors of the event
seen in LASCO.  Beginning 05:24 UT a faint CME from AR 10105 [S7; W44]. To
the SS East of the region a CME occurs from AR 10114 beginning 06:00 UT
located at [S12; W28]. A southward dimming is seen with this CME.  EIT
sees a bright flare from AR 10114 in the 06:36 UT image.  The flare seems
to have started shortly before this image but we lost the 06:24 UT frame.
A bright long duration flare is seen with wide south directed EIT wave and
CME and post loop arcade.  GOES shows a C8.6 xray flare of AR 10114 about
this same time. This was probably associated with the HALO seen in EIT and
LASCO.

The width of the HALO seen in LASCO is very hard to determine if the cause
was multiple events.

Images and movies of this event are available at:

ftp://ares.nrl.navy.mil/pub/lasco/halo/20020907/

Best reguards

Kevin Schenk
EIT and LASCO Operations
NASA-Goddard Space Flight Center, USA