"If you wish to make an apple pie truly from scratch, you must first invent the universe."

— Carl Sagan



Caldwell 23



Why stars are so Blue/Cyan?

why so blue

I think they are blue because the exposure took one hour and twenty minutes in total. The scope was going slowly out of focus due to temperature shift. Since blue was the last exposure, the blue image had the more bloated stars. When I combined this resulted in a blue halo/cast around every star.

min filter

Select the stars
apply min filter
fade the effect
Will be a LOT less bloated
Try only for the B channel 1st