Halo CME Mail

Date: Fri, 25 Oct 2002 13:07

From: Gareth Lawrence

Subject: Full Halo CME on 2002/10/25, frontsided

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UCMEO 93001 21025 1900/
21025 60950 91542 0001/ 360// 223// 40789
21025 60612 91000 21904 1//// 2112/
99999

PLAIN

BT

LASCO and EIT observed a full halo CME on 2002/10/25. The
event was first observed in C2 at 09:50 UT as a bright loop
front over the SE limb; by 10:06 UT the C2 occulting disk
was surrounded, though emission over the N pole was fainter.
The front first appeared in C3 at 10:42 UT with full
coverage of the C3 occultor at that time. The mean
plane-of-sky speed for this event was 789 km/s at PA 169,
with moderate deceleration through the fields of view.

The CME was most probably associated with a large eruptive
filament in the SE quadrant, which EIT observed between
06:12 - 10:00 UT. The eruption was centred ~S20E42 but
the prominence was discernible over to S04E19 and with
clear non-radial expansion/propagation. GOES does not
record any significant on-disk events around the time.
As luck would have it, EIT was observing in the 304A
bandpass at 12-min cadence at the time, and this is the
best for of the four for prominence/filament observations .
It is believed that both an EIT wave and dimming were
observed in association with this event, but these
phenomena are not well observed in 304A images.

Movies and images of this event are available now at:

ftp://ares.nrl.navy.mil/pub/lasco/halo/20021025

Please note that the movies clearly show an earlier
event in the SE that is not thought to have a
significant component along the sun-earth line.
Please note also that the most recent LASCO/EIT
images show another (fainter) full halo CME in
progress, first seen in the SE and over the S pole.
This event has been determined backsided on the
evidence of the EIT images.

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 001,                         +1-301-286-3447       |
| Greenbelt, MD 20771.                   Fax:    +1-301-286-0264       |
++