SOLAR OBSERVATIONS Last updated: 19 April 2001

Subject:	huge sunspot is back
Sent:	Thursday, April 19, 2001 04:50:44
From:	sherrodc@ipa.net (Clay Sherrod)
For all of our ETX users out there with solar filters (and naked eye
observers who have protective filters) the source of the LARGEST SOLAR
FLARE in HISTORY is back.

That's right.....sunspot # 9393 has returned on the eastern limb (edge)
of the solar disk and is still as large as ever.  Now it appears to be
compacted into one huge group, rather than many individualized spots
hovering about one or two very large spots as it was about two weeks
ago.

In March, 9393 became naked eye for weeks and resulted in the largest
solar flare ever recorded, fortunately one that occurred just prior to
the sunspot turning away from Earth on the western limb.  At its largest
on March 28, sunspot 9393 attained a TOTAL AREA  that was 14 TIMES THE
SIZE OF THE EARTH!!

This sunspot also created fantastic northern light (aurora borealis)
displays as far south as Southern California, Mexico, the tip of Texas
and southern Florida.  Many ETX users (the ETX scope is PERFECT for
observations of the sun when properly filtered) took excellent film and
digital photographs that were published here on the Mighty ETX site.
This one from Mike Weasner when the sunspot and its output were still
growing shows the huge size of this sunspot relative to the entire
near-one-million-mile diameter of the sun.





Observers who are interested in this sunspot, should visit my OBSERVING
GUIDE:  "Observing the Sun: The Human Star" posted here on this site
under the Observing Guide section at
www.weasner.com/etx/ref_guides/sun.html for details on proper
magnifications, sunspot classification, sunspot counting and
identifications of the many features afforded by so large a sunspot
group.

As the sun rotates just under 30 days, it will take about 14 days from
first appearance on the EAST limb for the spot to rotate all the way
across the facing disk of the sun toward Earth.  That means, not only do
you have a two-week window in which to observe the fantastic sunspot and
its aurorae, but also that we, on Earth, have a two week period in which
we could well be exposed to yet more huge outbursts of solar radiation.

Brian Sherrod, an ETX 90 user and avid HAM operator at w5ami in
Arkansas, reported such high radio propagation from the last "visit" of
the sunspot's energy (high ionization in the Earth's atmosphere) that
"skip" allowed him worldwide coverage through the two week period, and
could even hear his own broadcasts in "echo mode" as they returned
through his transmitter via a trip around the world as he was
communicating to receivers only hundreds of miles away!

The spot during its last trip also causes considerable satellite and
power grid failures (temporary, thank goodness).  In New England,
several power grid disruptions occurred that knocked out power for
several hours each, as did also happen in many Canadian provinces.
Likewise, AM broadcasts were reported to be totally masked for several
days throughout the world, and short-range communications on all AM
bands were likewise masked for periods of time.

You are encourage to visit our Sun and report your observations during
the next two weeks here on Weasner's Might ETX site.  REMEMBER:  proper
solar filter protection is required, both for your telescope and when
viewing naked eye.  Although the ancient Chinese astronomers recorded
naked eye sunspots for thousands of years by watching the rising and
setting of the bright sun through obscuring clouds and haze to block the
light.....this is NOT recommended!

Clay Sherrod
Arkansas Sky Observatory
Conway / Petit Jean Mountain
Arkansas

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