Need Help identifying this feature on my out of focus star.

[Astroman (Andrew Wall)]

Hello all,

I need to know what the odd shaped bumps are on the left hand side of this out of focus star image. I need to see if it's the cause for some odd shaped stars I am getting. They look like peanuts..

The star was Sirius and it had almost just crossed over the Meridian, so it was fairly high.

[The_bluester (Paul)]

I have an SCT but the last time I had a bump like that a bit of dust had settled on my secondary.

[PeterM]

Looks like turbulence.
This maybe useful
https://www.willbell.com/tm/tm5.htm

Cheers
Peter

[Astroman (Andrew Wall)]

Thanks for the comments, yes Peter looks like I need to let the mirror cool a little more before attempting this, I thought it was good enough, obviously not.

I think the triangular thing on the Left is the secondary mirror clip. I will be doing a Mirror cell modification to the scope this afternoon so hopefully it will help collimating the mirror better.