Solar Activity 21 April2021

[Merlin66]

Some CaK and Ha images from yesterday.
The AR 2815/AR2816/AR2817/AR2818 still showing some detail
The penultimate image is one where flats have been successfully applied during the acquisition using FireCapture. The last image shows a typical flat with the annoying NR

[PeterM]

Well done Ken. That first one is the killer image for me, comes up beautifully on the 27inch monitor. Bravo! Clouded here today so there goes my planned one hour AR animation... next week, looks like there is another AR on the way.

[John W]

Nice set of images ken, esp. the CaK ones. Regards, John W.

[Eris]

A great set of images Ken. It's good to see that you have been working on an effective strategy for tackling those pesky Newtons Rings. Excellent stuff. Well done.:thumbsup:

[Merlin66]

Gerard,
Thanks.
I’m just putting the final touches to the write-up on the use of full disk flat filters to suppress NR.
I hope others will find it useful.