'Full' Halo CME on 2003/10/23, frontsided *LINK*

[Peter Kuklok]

FYI, Halo CME Mail vom LASCO-Team:

'Full' Halo CME on 2003/10/23, frontsided

LASCO and EIT observed a 'full halo CME' on 2003/10/23. The
event was first observed in C2 at 08:54 UT as a bright loop
front over the E limb; this had developed to a full halo
CME by 00:30 UT, albeit faint in the W. The front first
appeared in C3 at 09:18 UT with full coverage of the C3
occultor by 10:20 UT. Note that the emission in the W is
brighter in C3 than C2, though still faint by comparison
to that in the E. The mean plane-of-sky speed for this
event was 1110 km/s at PA69, with possible evidence for
moderate deceleration.

The CME was probably associated with an X5.4 X-ray flare
observed by EIT between 08:24 - 09:24 UT, centered at S10E55
with peak emission at 08:36 UT. Note that very strong emission
is also seen to the E of this, around S10E75. GOES records
this flare from AR 0486 between 08:19 - 08:49 UT with peak
emission at 08:35 UT. A very large EIT wave, and dimming
were observed in association with this event. Considering
the location of the flare, the faint emission in the W
hemisphere and ongoing activity in the region between
AR 0486 and AR 0484 centered N04E13 during this period,
this event has been determined frontsided.

Movies and images of this event will shortly be
available at:

ftp://ares.nrl.navy.mil/pub/lasco/halo/20031023

Best wishes,

Gareth Lawrence.