aktuelle Halo CME Mail

[Peter Kuklok]

LASCO and EIT observed a full halo CME on 2002/05/22. The
event was first observed in C2 at 03:26 UT as a faint loop
front over the SE limb; by 04:06 UT the C2 occulting disk
was surrounded by a thick bright front in the W extending
over both poles and fainter extensions in the E. The front
first appeared in C3 at 03:42 UT with full coverage of the
C3 occultor by 04:18 UT. The plane of sky speed of the front
was measured as 1496 km/s at PA 237 (SE) with very slight
deceleration through the coronagraphs' fields of view.

The CME was most probably associated with a large, bright,
fast eruptive prominence that EIT observed between 03:00 -
04:24 UT, in the region of the disk centred on S19W56.
GOES notes a disappearing filament between 03:18 - 05:00 UT
and a C5.0 X-ray flare between 03:18 - 05:02 UT with peak
emission at 03:54 UT, from S30W34. Neither an EIT wave nor
a 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/20020522

and please note that two other large events have been
deliberately included in the movies. The first is a CME
seen in the NE from 2002/05/21 21:50 and is probably
associated with a M1.5 X-ray flare in AR9960, N17E38.
The second is a CME seen in the SW from 2002/05/21
23:50 and is probably associated with a C9.7 X-ray
flare in AR9948, S25W64. Due to the extents of the CMEs
and the positions of their apparent source regions
there is reason to believe that either or both might
have a small earth-directed component; however
both are likely to be overtaken by this third event,
which is the fastest of the three. The full halo CME
and be seen running into the later partial halo CME
in the outer region of the C3 field of view, and the
first partial halo CME is significantly slower. We
therefore consider that a single complex ejecta at
1AU is the most likely outcome of these three events.
For reference the speeds of the two partial halo CMEs
average to 863 km/s and 1333 km/s .

Best wishes,

Gareth Lawrence.

Quelle: http://lasco-www.nrl.navy.mil/mail/halo_mail/168.html