Date: Tue, 2 May 2006 10:28
From: Guillermo Stenborg
Subject: Frontsided Event on 2006/05/01
Status: O
UCMEO 93001 60502 1430/
60501 61530 80342 0001/ 360// 113// 20330
60501 61433 81634 32917 10875 1112/
99999
PLAIN
LASCO/EIT observed a frontsided event on 2006/05/01. The event was first
seen in C2 at 15:30 UT as an extremely faint and diffuse brightening just
appearing above the W Limb [1]. It extends up to past the N Pole by 16:30
UT. Also some extensions on S by 18:06 UT. A very ragged loop front
follows on SW by ~ 17:06 UT [2]. Finally, a system of faint loops develops
on W by 18:30 UT [3], moving out much more slowly than [2]. The complex
event appears as a faint full halo event in the C2 FOV (though the signal
in the eastern hemisphere is barely discernible). Feature [2] is clearly
discernible in C3, where it is first seen appearing on SW by 18:18 UT. By
22:18 UT, Feature [3] makes its appearance above the W Limb in the C3 FOV.
There is no detectable signatures of the event in the western hemisphere.
The mean plane-of-sky speed based in both C2 and C3 (only few points at
the beginning of the FOV) data is as follows:
Feature [2] at PA 222: ~330 km/sec (showing practically no acceleration)
Feature [3] at PA 270: ~140 km/sec (showing practically no acceleration)
GOES recorded a long duration C1.0 X-ray flare on NOAA AR 10875 (S17W29)
between 14:33 - 16:34 UT with peak emission at 15:35 UT. EIT 195 images
show the development of a frontsided CME characterized by the formation
of a dimming region to S of AR 10875, then E and then N all between around
14:24 - 15:48 UT. Nice post-flare loops afterward.
In summary, the event has therefore been determined as a very faint
Full Halo Event (only visible in C2), frontsided, associated to a long
duration C-class X-ray event on NOAA AR 10875.
LASCO movies and images of the event will shortly be made available at:
ftp://ares.nrl.navy.mil/pub/lasco/halo/20060501
Best wishes,
Guillermo Stenborg
++
Dr. Guillermo A. Stenborg
SOHO-LASCO Operations Scientist,
CUA, MC 612.5, Bldg 26, Rm 001, F: +1-301-286-0264
NASA Goddard Space Flight Center,
Greenbelt, MD 20771. P: +1-301-286-2941
e-mail: stenborg@kreutz.nascom.nasa.gov
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