Halo CME Mail

Date: Thu, 8 Feb 2001 14:52

From: Gareth Lawrence

Subject: Backsided halo CME on 2001/02/07

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LASCO observed a very faint full halo CME on 2001/02/07. A faint front
was fisrt visible in C2 at 10:06 UT, over the W limb. By 11:54 a
faint extension was visible around the entire C2 occulting disk. The
westerly front first appeared in C3 at 11:42, with full coverage by
13:42, though this is hard to discern without viewing a running
difference movie since the majority of the images taken during this
period were at a reduced exposure time of ~5 sec in order to observe
a sungrazing comet without saturation.

EIT did not observe any event that could be asscociated with this CME.
Additionally there were no GOES X-ray signatures within a reasonable
timeframe (only three for the day, in fact). As a result this event
has been determined backsided.

Also, I have noticed that the last three halo alerts that have been
sent out have been dated 2000 rather than 2001 in the Subject line.
I apologise for this careless mistake and for any confusion it may
have caused. The information in the body of the email was correct in
all three cases, in particular the UCMEO formatted data for SEC.

Best wishes,
        Gareth Lawrence.

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| Gareth Lawrence,                 E-mail:grl@ajcannon.nascom.nasa.gov |
| SOHO-LASCO Operations Scientist,                                     |
| CUA, Mail Code 682.3,                                                |
| NASA Goddard Space Flight Center,      Phone:  +1-301-286-3412       |
| Building 26, Room G-1,                         +1-301-286-3447       |
| Greenbelt, MD 20771.                   Fax:    +1-301-286-0264       |
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