Date: Sun, 2 Jan 2005 15:53
From: Guillermo Stenborg
Subject: Another faint and asymmetric 'full' halo event on 2004/12/30, frontsided
UCMEO 93001 50102 1550/
41230 62230 80842 0001/ 360// 123// 21150
41230 62202 82228 14604 10715 1122/
99999
PLAIN
BT
This is the report of the second 'full' halo event observed by LASCO/
EIT on 2004/12/30. This second event was first seen in C2 at 22:30 UT
just appearing above the E Limb. The bulk of the mass develops toward E,
though by 23:30 UT, faint extensions can be seen surrounding the C2
occulting disk. By 00:54 UT on next day, a ragged (faint) front can be
seen developing above the W Limb, with ragged extensions up to the S
Pole. The event is first seen in C3 at 23:18 UT above the E Limb; by
23:42 UT faint extensions surround the C3 occulting disk. The mean
plane-of-sky speed of the LE (based on C3 data) at PA 90 was ~ 1150 km/sec
(showing practically no acceleration).
As mentioned in previous report, GOES reported high X-ray activity
during the day with a couple of M flares and multiple B- and C- class
X-ray flares from NOAA AR 10715. In particular, it is worth to mention
the following events, very likely associated with the C2/C3 signatures
described above:
- a C4.1 (N03E46) between 21:41 - 21:56 UT, peak emission at 21:52 UT,
- a M4.2 (N04E46) between 22:02 - 22:28 UT, peak emission at 22:18 UT,
- a C1.2 (N03E47) between 00:30 - 00:54 UT (on 12/31), peak emission at
00:43 UT (on 12/31).
EIT 195 images show a brightening on the aforementioned AR starting
at 21:49 UT followed by a much stronger one at 22.12 UT. An intensity
disturbance (wave) is seen developing by the time mainly toward N, S,
and W of the AR. The ejection of a filament to NE, N, S, and W of the
AR can be seen between ~ 22:24 - 22:36 UT.
In summary, the event has therefore been determined as an asymmetric
'full' halo event, frontsided.
Movies and images of the event will be made available by Monday 01/03 at:
ftp://ares.nrl.navy.mil/pub/lasco/halo/20041230b
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NOTE: Typo on previous message:
On previous massage where it says:
- a C1.3 (N04WE52) between 10:10 - 10:19 UT, peak emission at 10:17 UT,
- a M2.2 (N03WE53) between 10:33 - 11:28 UT, peak emission at 11:16 UT,
- a C2.6 (N05WE52) between 12:14 - 12:19 UT, peak emission at 12:17 UT,
it must say:
- a C1.3 (N04E52) between 10:10 - 10:19 UT, peak emission at 10:17 UT,
- a M2.2 (N03E53) between 10:33 - 11:28 UT, peak emission at 11:16 UT,
- a C2.6 (N05E52) between 12:14 - 12:19 UT, peak emission at 12:17 UT,
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Best wishes,
Guillermo Stenborg
++
Dr. Guillermo A. Stenborg
SOHO-LASCO Operations Scientist,
CUA, MC 682.3, 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
++