Friday, 1 June 2012

AR11476 Returns!

AR11476 Returns! A great sunspot group is the product of a much larger region of magnetic polarity - called by some :"activity nests". While sunspots arise only where emerging fields exceed ~1500 gauss and are fairly small, the whole region or "nest" can be huge, ten times larger than the spots. Here we see (SDO EUV 304A) the region that produced 11476 a month ago returning at the sun's NE limb. There are spots here, not seen as the nest saturates the SDO detector. White light will show them well. In the corona above the site there's lots to see: PFL are post flare loops above a sunspot and surges or filaments hover above. As well a large coronal hole has developed 30 deg west of the site (black arrows). Is it involved with the "nest" in any way? How long will the nest last - what will it produce during this transit?
"Activity Nest" is a useful term used by Schrijver and Zwaan in "Solar and Stellar Magnetic Activity" Cambridge Uni. 2008. P142~

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