Extra diffraction spike?

[astromerlin]

Hi all, Not having been out there for a while I managed to setup out there last night and had to go through the process of polar alignment and the usual software crashes.

I then checked the collimation and setup the webcam in the ota, I noticed that when focused on a bright star I have an extra diffraction spike going diagonally across the star from upper left to lower right which is larger and extends longer than the normal cross spikes you get.

I would have taken an image to show but with all the other problems I had no images were taken last night. I even had to leave the tripod out as it had frozen solid to the ground.

Anyone have an idea why the extra spike?

[Tinners]

Spider?

[davew]

Hard to tell without a picture but it could be the focus tube intruding.

Dave.

[astromerlin]

Hi thanks for the help. I've been doing search on the forum and it seems like it could be quite a few things from stray light entering the ota to obstructions in the light path. When I get the chance again I'll post a pic.