Hello all, my first post here.
I have a Celestron CPC 925, which I bought new in 2008. I used it mainly for visual and some casual astrophotography. In about 2012 the arival of my daughter and busy career took me away from astronomy and the scope was left to gather dust. My interest in astronomy was revitalised by Comet Neowise in 2020 and I've started to get into more serious astrophotography.
But, the scope has an optical artifact/defect in the out-of-focus disk of stars that looks like a crack.
I can see no obvious physical damage to the corrector plate or primary mirror. I've not yet worked up the corrage to take off the corrector plate to inspect the secondary.
I've attached some images, using Procyon, to illustrate the issue. They run from way out of focus to in focus.
I wonder if anyone has any suggestions as to what could be causing this and whether it is a significant problem.
Many thanks.