LASCO and EIT observed a full 360 degree halo CME yesterday, 1999/09/20.
This was a very faint event in LASCO, visible only in running difference
movies. The CME first appeared in C2 at 06:06 UT, and in later frames it
was visible as a ring extending all the way around the occulter.
The measured plane-of-sky speed in C3 is about 450 km/s at PA 0
(North pole). Because this is a faint event, and the leading edge is
rather fuzzy, this is a very approximate speed.

EIT observed a filament eruption from the southern portion of the solar
disk, close to central meridian, beginning at about 03:48 UT. Following
the filament eruption, a bright arcade of loops formed in the same
location, beginning at about 06:00 UT. This is the most probable source of
the halo CME.

Images and movies of the event are available at the LASCO ftp server:

Best wishes,

Simon Plunkett.

| Simon Plunkett,              E-mail: |
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