[Astroalerts] Very Large Sunspot Produces Multiple Major Solar Flares

[Cary Oler]

                            A s t r o  A l e r t
                               Sun-Earth Alert

                          Solar Terrestrial Dispatch
                            http://www.spacew.com

                              15 January 2005

MULTIPLE MAJOR FLARES FROM A VERY LARGE SUNSPOT

     A very large sunspot is now easily visible to the unaided eye. The
sunspot complex known as Region 10720 (or abbreviated as just Region 720) is
a huge mass of magnetic fields. The magnetic fields protrude through the
"surface" of the Sun and cool the region where they protrude. The cooler
region appears dark against the brighter background. This darker "spot" is
known as a sunspot. Most sunspots are relatively small, but Region 720 is
quickly becoming a behemoth. It is currently capable of swallowing 5 entire
Earths. And the powerful magnetic fields emanating from its core are the
source of some of the most energetic explosions known to man. Within a 6 hour
period commencing early on 15 January, Region 720 used its tangled mass of
magnetic fields to unleash three major solar flares, including one X-class
event. Although the X-class flare was brighter in x-rays (reaching a class
X1.2 intensity), the last of the three events (a major class M8.6 event) was
by far the most energetic overall. Whereas the X-class flare lasted only
about 20 minutes in duration, the strong M-class flare lasted almost one and
a half hours, produced intense radio bursts, and succeeded in accelerating
energetic protons Earthward.

     The major class M8.6 solar flare is believed to have been associated
with an Earthward-directed coronal mass ejection, although the data to
confirm this is not yet available. An analysis is still in-progress, but
it is likely that we will see a moderately strong impact at the Earth from
this coronal mass ejection sometime on 16 January that should last into 17
January (UTC time). A middle latitude auroral activity watch will very likely
be released for this event within the next 24 hours. North Americans should
probably be alert for northern lights activity on the evening of 16 November,
but anytime during the next week could yield surprises.

     Region 720 is expected to continue to produce strong solar flare
activity for as long as perhaps the next week. It will be capable of throwing
additional mass Earthward over at least the next several (3-5) days, with the
next 2 to 3 days being the most sensitive.

     It is interesting to note that the Sun is within about 2 years of
reaching the minimum of the sunspot activity cycle. Todays energetic solar
activity reaffirms the fact that the most energetic solar activity tends to
occur during the declining years of the sunspot cycle. Several more solar
outbursts (unrelated to Region 720) will be possible before we reach the
sunspot minimum in late 2006 or early 2007.

     Supporting imagery for this event is available at:
http://www.spacew.com/astroalerts.html


** End of Astroalert **