Addendum to the "Return of the King" AstroAlert

[Peter Kuklok]

A s t r o A l e r t

Sun-Earth Alert

Solar Terrestrial Dispatch

http://www.spacew.com

17 June 2003

ADDENDUM TO THE "RETURN OF THE KING" ASTROALERT

Old Region 10365 noted in the last AstroAlert is the probable source of
the X-class flare of 15 June noted in the last AstroAlert. NOAA has numbered
this sunspot complex as Region 10386. It appears to have decayed a fair
amount since it last left the western limb in late May. Nevertheless, the
region still appears to be capable of packing a punch. It is also still too
close to the limb to perform a detailed analysis.

SOHO imagery taken during the flare and played back recently have
indicated that a full halo coronal mass ejection was associated with this
event. This means that mass from the CME was probably directed Earthward,
despite the very poor position of the sunspot group when the energetic event
occurred and contrary to the last AstroAlert that assumed mass was not
directed Earthward given its poor limb position.

The plane of sky velocity of this coronal mass ejection was also
unusually fast, estimated at slightly over 2,000 kilometers per second, or
over 1,250 miles per second. The flanking edge of this disturbance could
reach the Earth on 18 June and linger perhaps through 19 June. This could combine
with anticipated effects of a solar coronal hole disturbance that is expected
to arrive on 18 or 19 June to prolong activity somewhat.

If additional energetic activity persists from this active region over
the next week or two (it might not), the Earth may observe periods of
potentially strong auroral storm activity. Sky watchers are encouraged to be
alert for potential favorable conditions supporting displays of the "Northern
Lights" during the next 2 weeks.

** End of the AstroAlert Bulletin **