PROM ALERT: If you have a solar telescope, take a look at the sun. Observers are reporting a large and beautiful prominence dancing along the western limb.
SOLAR WIND LOSING POWER: In a briefing yesterday at NASA HQ, solar physicists announced that the solar wind is losing pressure, hitting a 50-year record low for the Space Age. This development has repercussions across the solar system: full story.
FADING SUNSPOT: A small sunspot emerges, flickers, and fades away in less than 48 hours, gathering attention once reserved for Jupiter-sized behemoths. Welcome to solar minimum.
This SOHO animation, spanning Sept. 21st to 23rd, shows the fleeting appearance of sunspot 1002:
The real excitement about the active region was not its size or duration, but rather its polarity. The orientation of the sunspot's magnetic field identified it as a member of new Sunspot Cycle 24. Because the year 2008 has brought so many blank suns, some observers have wondered if we are ever going to climb out of the ongoing deep solar minimum. Sunspot 1002 is an encouraging sign that the 11-year solar cycle is indeed progressing, albeit slowly.
more images: from Alan Friedman of Buffalo, New York; from N. Hebert et al. of South Portland, Maine
SUNRISE AT THE SOUTH POLE: On Sept. 21st, Ethan Dicks looked out the window of his office and saw the sun for the first time in 6 months. He quickly grabbed his camera and snapped this picture of sunrise at the South Pole:
"I am a researcher for the University of Wisconsin-Madison, running
IceCube, the large (1 km3 when completed) neutrino telescope that's under construction a mile below the ice near the South Pole," explains Dicks. "The past six months have been almost nothing but night; it's good to see the sun again."
He took the picture a full day before the Sept. 22nd equinox--the "official" date of sunrise. Geometrically, the sun should've been mostly below the horizon at the time, but refraction by the dense polar atmosphere lifted the image up for all to see.
"Polar regions are famous for mirages and early explorers sometimes wondered what was real and what illusion," notes atmospheric optics expert Les Cowley. "In Dicks' picture, several air layers of different temperature have distorted and sliced the sun. Its rays are bent as they pass between the layers to form multiple images, some inverted and some upright."
Dicks is a veteran observer of South Pole sunrises. "This is my third winter here," he says. Some sunrises are heralded weeks ahead of time by a diffuse glow on one side of the sky and the retreating shadow of Earth ("a dark blue band topped by a fringe of magenta") on the other. Eventually a sliver of sun appears, circling the horizon for days, growing in size, until finally the sun emerges in full. "When it's clear, the show is amazing. This year, we were mostly clouded out until Sept. 21st. I feel bad for folks on their first and maybe only winter-over; they missed the full sunrise."
When you're at the South Pole, though, even a fraction of sunrise can be a wonderous thing.
Sept. 2008 Aurora Gallery
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