Maybe this is or isn't sustag related--though I think most things
are--but I wanted to report back to y'all since I'd asked here
whether anyone had seen the kick-butt auroral display on August 27.
And I heard from quite a few people that they had.
Two weeks ago I learned that on August 27, a gamma-ray flare from a
magnetar in the constellation Aquila (the Eagle, near Sagittarius),
and 20,000 light years from the earth, flashed thru our planet. Its
emissions were so strong they caused the earth's ionosphere to glow,
for a short time.
I wonder whether what we saw was the energies thrown off by that
distant starquake.
Here's the lead from Stanford's press release:
"Sept. 29, 1998: On the night of August 27th Earth's upper
atmosphere was bathed briefly by an invisible burst of gamma- and
X-ray radiation. This pulse - the most powerful to strike Earth from
beyond the solar system ever detected - had a significant effect on
Earth's upper atmosphere, report Stanford researchers. It is the
first time that a significant change in Earth's environment has been
traced to energy from a distant star."
Magnetars are kinda like neutron stars--really dense,
squished-together balls of stellar stuff. They apparently happen
when a star goes nova and collapses into a 12-mile-wide sphere whose
mass is about equal to that of our sun. Their surfaces are iron, and
they spin rapidly. They also have extremely powerful magnetic fields
(hence the name). These fields are so powerful they can periodically
tear the star's surface apart, producing a starquake and huge pulses
of gamma- and X-ray radiation.
Says NASA: "According to the magnetar theory, the common flashes
that are the hallmark of SGRs are due to starquakes. As a magnetar's
huge magnetic field drifts though the neutron star, the magnetic
strain on the iron crust causes it to deform, often breaking it. Like
an earthquake, this vibrates the star with seismic waves, and drives
shaking magnetic waves outward to energize particles outside the star
and emit flashes of soft gamma-rays. To cause starquakes, the
magnetic field must be enormous - at least 1014 gauss, at least 100
times stronger than a "normal" pulsar!"
Before this event, magnetars were theorized but this event confirmed
their existence.
Here's NASA's release:
http://science.nasa.gov/newhome/headlines/ast29sep98_1.htm
Here's Stanford's, on the NASA site:
http://science.nasa.gov/newhome/headlines/ast29sep98_2.htm
Here's the magnetar Web site:
I'm about blind-drunk with Wonder over this.
peace
misha
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Michele Gale-Sinex, communications manager
Center for Integrated Ag Systems
UW-Madison College of Ag and Life Sciences
Voice: (608) 262-8018 FAX: (608) 265-3020
http://www.wisc.edu/cias/
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