Schwache CME, Halo-CME-Mails vom 05.+06.07.2005

[Lutz Schenk]

Hi Zusammen,

die C-Class Aktivität der Sonne hat ja in den letzten Tagen einige schwache (faint) Full- und partial Halos gebracht.

Mal sehen ob der M5,1 vorhin was gebracht hat. Leider noch keine Lascos dazu vorhanden.

Größe aktivität ist davon wohl nicht zu erhoffen, aber anbei trotzdem mal die Halo-CME-Mails.

Viele Grüße,

Lutz


UCMEO 93001 50706 1535/
50705 61530 80318 0001/ 360// 113// 20794
50705 61452 81549 23310 10788 1112/
99999

PLAIN

BT


LASCO/EIT observed a faint 'full' halo event on 2005/07/05. The
event was first seen in C2 at 15:30 UT above the SE limb, as
a bright loop-like front with apparently extremely faint extensions
above the S Pole. By 15:54 UT, an apparent distinct front can be
discerned behind, developing mainly toward E. By this time on, the
faint extensions mentioned above extend up to the W Limb, becoming
brighter there. There is a small C2 data gap after 16:30 UT, the
next C2 image available corresponding to 18:06 UT. At that time,
very faint extensions can already be seen above the N Pole. The
event was first seen in the C3 FOV at 16:18 UT, above the SE limb,
with very faint extensions developing above the S Pole. A second
front is clearly visible above the E Limb by 17:42 UT. By 19:42 UT,
the C3 occulting disk appears completely covered. The mean plane-of-
sky of the LE of the two main features mentioned above is given
below (based on C3 data):

Outermost front at PA 125: 794 km/sec
Second front at PA 085: 654 km/sec

GOES reported a C1.3 X-ray flare on NOAA AR 10788 (S10E33) between
14:52 - 15:49 UT with peak emission at 15:26 UT. EIT 195 running
difference images show a relatively strong brightening on AR 10788
at 15:24 UT, which was preceded by signatures of a CME developing
toward SW since 15:00 UT. EIT 195 images show, starting at 15:00 UT,
the dimming of a region to S-SE of the AR.

In summary, the event has been determined as a faint and asymmetric
full halo event, frontsided, associated to C-class X-ray activity on
NOAA AR 10788.

Movies and images of the event will shortly be made available at:

ftp://ares.nrl.navy.mil/pub/lasco/halo/20050705


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
+--------------------------------------------------+


UCMEO 93001 50707 1625/
50706 62126 91442 2753/ 115// 123// 20275
50706 ///// ///// ///// ///// ///2/
99999

PLAIN

BT


LASCO observed a faint Partial Halo Event on 2005/07/06-07. The event
was first observed in C2 on 07/06 at 21:26 UT just appearing above the
N Pole as a very faint and diffuse wide front. It develops as a system
of wide and expanding loop fronts, the subsequent expanding fronts mainly
appearing above the NNE limb until around 05:26 UT on 07/07. The event is
first seen in C3 at 01:42 UT (on 07/07) above the NNE limb. By 09:42 UT,
the whole event spans in C3 ~ 200 deg (from PA 275 - 115, though the
limit on W is not well defined). The mean plane-of-sky speed of the LE
at PA 028 was ~ 275 km/sec (based on C3 data).

GOES reported multiple C-class (impulsive) X-ray activity on NOAA AR
10786 all along 07/06. In particular, after 17:00 UT we have:

- a C5.9 (N09E14) peaking at 17:49 UT,
- a C1.4 (N10E14) peaking at 18:46 UT,
- a C1.0 (N10E12) peaking at 20:22 UT, and
- a C1.0 (N09E12) peaking at 21:24 UT.

EIT 195 images show a relatively strong brightening on AR 10786 at
17:48 UT, and some minor brightenings later that roughly match the
time of the X-ray spikes. Some time after the brightening at 17:48 UT
(i.e., starting at ~ 19:48 UT), a slight dimming region can be seen
developing rather far to the ESE of AR 10786.

In summary, the event has therefore been determined as a Partial Halo
Event. However, despite the frontsided activity observed, I don't find
it conclusive to catalog the LASCO event as frontsided. Therefore,
there exist the possibility that the event may have been backsided.

LASCO movies and images of the event will shortly be made available
at:

ftp://ares.nrl.navy.mil/pub/lasco/halo/20050706


NOTE:

- Please note a typo error on my previous Alert (Subject: Faint Full
Halo CME on 2005/07/05, frontsided).

Where it says:
"... the dimming of a region to S-SE of the AR."

it must say:
"... the dimming of a region to S-SW of the AR.".


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
+--------------------------------------------------+