Joe Capra’s recently released time lapse of aurora over Iceland and Greenland
Nice work! Take a peek at Joe Capra’s recent 10-day shoot of the aurora and you’ll be licking your chops to fly to Greenland on the next available plane. Capra used three Canon 5D Mark III cameras with various Canon lenses to shoot hundreds of individual photos that he later stacked into a video. The reflections on ice and water are spectacular.
A low, green aurora in the northern sky on November 19th sparked by a coronal hole. Credit: Bob King
Here in the northern U.S., the aurora’s been snoozing. Even though gusts of solar wind from a leaky coronal hole have tickled Earth’s magnetic domain the past few nights, conditions have remained below storm level. The aurora’s been a constant but quiet presence like the embers of an overnight fire.
More low aurora simmers in the north last night (Nov. 20) around 11 o’clock. The band of northern lights, called the aurora oval, hovers directly over places like Iceland and Greenland, so people there get to see displays nearly every dark night of the year. It takes coronal holes, flares and other kinds of heightened solar activity to expand the oval so skywatchers in lower latitudes get their chance. Credit: Bob King
Expect the same horizon-hugging aurora for the next couple nights as the hole in the Sun’s magnetic canopy continues to send pinging particles our way.
That giant sunspot that’s made it through a second rotation of the Sun has been nothing but a tease when it come to flares. On its return a week ago, the group possessed the magnetic complexity to unleash powerful X-class flares, but so far, all’s been quiet on the solar front.
Sunspot group 2209 (older 2192) mimics a bear claw in this photo taken on November 19th by French amateur astronomer Philippe Tosi with an 8-inch telescope. Earth shown for size. Click to see more of his amazing high-resolution Sun image. Credit: Philippe Tosi
Flares aside, the region makes a great sight in the telescope. Shaped like a bear claw, the main spot in the group still spans more than three Earths. Philippe’s photo beautifully shows the fiber-like texture of the outer penumbra fringing the darker umbras.
Sunspots are cooler regions on the Sun’s surface – the reason they appear darker – where strong magnetic fields insulate those areas from their hotter surroundings. Notice the rice grain texture of the background. Called granules, each one’s about the size of Texas and represents an individual cell of hot solar gas rising from below like bubbles in a pot of boiling water. At the surface, the gas cools and sinks back down along the tiny, dark channels separating one from another. Re-heated, they rise again.