Each day can have a beautiful ending as the Sun sets below the western horizon. This week, the setting Sun added naked-eye sunspots to its finale, as enormous active regions rotated across the dimmed, reddened solar disc. Photographer Jens Hackmann
Near the Sun’s center in this closing telephoto view from November 7th are sunspots in Active Region 1339. Responsible for a powerful X-class flare on November 3rd, Active Region 1339 is larger than Jupiter. In the foreground, the ruined tower of a medieval castle stands in dramatic silhouette. Located in Igersheim, Germany and traditionally known as castle Neuhaus, it might be named Sunspot Castle for this well-composed scene. apod
The black and white images show the magnetic field – the field is pointing toward us where it is white. The leading spots all have an intense negative polarity and the following spots are mostly positive.
The two polarities are pretty well separated and fairly stable, which is why this region hasn’t produced even more dramatic activity. The biggest explosions happen when complex magnetic regions annihilate each other.
The glittering moving features around the spots follow the crests of magnetic waves. Not much new flux is emerging into this mature region, but there is a lot going on in the vicinity – and just about everywhere else too if you look carefully. The surrounding filamentary structures are weaker field regions that appear bright in intensity.
The movie with the granular yellow background shows the Sun’s surface brightness. Sunspot group 11339 is already large when it rotates around
to the front side of the Sun. The umbra is the darker, cooler part where the magnetic field is very strong and vertical. The surrounding orange penumbra appears very dynamic because waves in the weaker horizontal magnetic field make it look like material is flowing out of the spot.
Watch how the darkest regions develop in time. The largest spot is more than five times the size of our Earth. What you cannot tell from these pictures is which direction the magnetic field is pointing.
Credit: NASA SDO