Sunspots 17th July 2025

[The Thing]

My first sunspots in a while, while I can't compete with Roberto this is the best I've achieved to date. This is a very large sunspot group, 4143, 4136, 4146, 4139 according to SolarHam.com so a very wide image covering about 1/3 the width of the sun at the latitude they are currently at. The ASI678 chip is wide format so well suited.

50% of 2000 frames (in Firecapture) stacked in ASIVideoStack 1.16.0, processed in LuckyStackWorker (htp://wilcokas.com/luckystackworker). I need to work out why the solar 'surface' has come out so granular, looks like a processing artifact...

Image date, time and location:   2025-07-17, 12:05 UTC, Manche, France
Telescope aperture and focal ratio:   Teleskop Service Classic Cassegrain 8" f12, fl 2463mm
Camera and filters used:   ZWO ASI678 OSC uncooled, no filters
Processing applied:   ASIVideoStack, LuckyStackWorker


Click for full size image

[Dave A]

Nice image Duncan
great Sunspots

[Carole]

Lovely sunspots Duncan but the background looks rather strange.  Looks more like Wallpaper than solar surface. 

[The Thing]

Lovley snpots Duncan but the background looks rather strange.  Looks more like Wallpaper than solar surface. 

Could just be the large FoV making the surface cells look smaller than we're used to or the 2 micron pixels having an effect. Sharpening and deconvolution coupled with smoothing has made it obvious by posterising the granulation.