Sunspot 2396 has grown rapidly over the past few days and yesterday I had a chance to quickly capture between the clouds. Sunspot 2396 stretches more than 150,000 km (93,000 miles) from end to end and that main spot itself is 3 times the size of Earth. Sunspot 2396 has a beta-gamma magnetic field and has the potential to emit an M-class flare but the chances appear to be subsiding as the sunspot turns to face away from the Earth.
We’re approximately 2 years past Solar Max, the point in its 11 year cycle where solar activity is at its peak and the sun’s magnetic poles switch. Its peak was expected in 2013 but fewer sunspots, flares, coronal mass ejections and increased aurora activity in the atmosphere were observed. Since then we’ve learned that the sun probably has its solar max in its north and south equator not quite at the same time making it appear quieter. So it’s good to see a large sunspot in this lull of activity.
The Active Region around Sunspot 2396 is huge, the largest core of that clustered group of sunspots is at least three times the size of the Earth. Sunspots appear darker than the surrounding surface because they are cooler with the lighter Penumbra surrounding the cooler central Umbra making it look black against the glowing surface of the sun. If these sunspots could be isolated, they would be brighter than a full moon.
This image is composed of approximately 20 x 1/320 sec exposures through a white light Baader solar film, Skywatcher 200p telescope, 3 x TeleVue Barlow lens and a Canon 1000D DSLR. Image copyright Nick Cook.