WILL ARCTIC SKIES TURN GREEN FOR CHRISTMAS? A minor stream of solar wind is approaching Earth. Estimated time of arrival: Dec. 24-25. No geomagnetic storms are expected, but the gaseous material could spark holiday auroras around the Arctic Circle. Aurora Alerts: SMS Text.
A SUNSPOT FROM THE NEXT SOLAR CYCLE: Breaking a string of 40 spotless days, a new sunspot is emerging in the sun's southern hemisphere. It comes from the next solar cycle. The unnumbered spot is inset in this map of solar magnetic fields from NASA's Solar Dynamics Observatory:
How do we know this is a new-cycle sunspot? Its magnetic polarity tells us so. Southern sunspots from old Solar Cycle 24 have a -/+ polarity. This sunspot is the opposite: +/-. According to Hale’s Law, sunspots switch polarities from one solar cycle to the next. This sunspot is therefore a member of new Solar Cycle 25.
Recently we reported that Solar Minimum has reached a century-class low. This sunspot, plus a few others like it earlier this year, affirm that Solar Minimum won't last forever. Solar Cycle 25 is showing signs of life. Forecasters expect the next solar cycle to slowly gain strength in the years ahead and reach a peak in July 2025.
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THE FAINTING OF BETELGEUSE: One day, perhaps in our lifetimes, perhaps 100,000 years from now, the red giant Betelgeuse will dim a little--and then explode. The supernova will rival the full Moon in the night skies of Earth and cast shadows after dark. This month, Betelgeuse has dimmed a little. So far it has not exploded. Alan Dyer photographed the star rising as usual with the rest of Orion on Dec. 21st:
"This is Orion rising over my home in Alberta, Canada, on a partly cloudy and foggy night," says Dyer. "Yellow-red Betelgeuse is shining at upper left, reportedly dimmer than usual."
Betelgeuse caused a sensation among professional astronomers earlier this month when Edward Guinan of Villanova University and colleagues reported a significant "fainting" of the star. "[Betelgeuse] has been declining in brightness since October 2019, now reaching a modern all-time low of V = +1.12 mag on 07 December 2019 UT," they wrote. "Currently this is the faintest the star has been during our 25+ years of continuous monitoring."
Astronomers have long known that Betelgeuse is on the precipice of an energy crisis. It's about to run out of fuel in its core. When that happens, the star will collapse and rebound explosively, producing the first known supernova in the Milky Way since 1604. Experts in stellar evolution believe Betelgeuse could die at any time during the next 100,000 years--a blink of an eye on time scales of astronomy.
The current dimming did not herald that final blast. Betelgeuse is also a slow variable star, and this seems to be no more than an episode of slightly deeper-than-usual dimming. Orion remains intact ... for now.
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CHRISTMAS GIFTS FROM THE EDGE OF SPACE: So far in 2019, the students of Earth to Sky Calculus have launched 41 space weather balloons to the stratosphere, measuring cosmic rays over 2 continents and 6 different US states. You can help them pay their helium bill by purchasing a Christmas gift from the edge of space:
Every item in the Earth to Sky Store has flown to the stratosphere alongside an array of cosmic ray sensors. Carried aloft by giant helium balloons, these unique gifts travel above 99.7% of Earth's atmosphere, experiencing space-like blasts of cosmic rays, extreme cold, and a wild ride parachuting back to Earth after the balloon explodes. Even Amazon doesn't carry items this far out.
Don't forget to enter coupon code "XMASRAYS" at checkout for a 10% holiday discount.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education
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