Strange glitch in stars? Pinched optics?

[Jamgood]

Hi all.

Hopefully someone can tell me what this is and how to fix it? Started happening a few weeks ago. Nothing had changed with the scope, no knocks, all fine and then all of a sudden I'm getting images like this and I can't for the life of me fathom it out.

I've recollimated the scope, several times, I've tried collimating while tightening and loosening the nuts but the mirror keeps on giving this strange (I don't even know what to call it) optical glitch?

All advice welcomed as I'm stuck and this is starting to waste many many hours of imaging time now. I'm sure someone has seen this before and knows the fix or is the mirror just done for?

[Davey-T]

Something encroaching on the optical path, end of focuser maybe, have you tried without the MPCC ?

Dave

[Jamgood]

11 minutes ago, Davey-T said:

Something encroaching on the optical path, end of focuser maybe, have you tried without the MPCC ?

Dave

I have tried without the MPCC as it has always worked. I will try it though and see. 

I've just been doing some diagnostic tests, (Still with the MPCC) pointing at different places in the sky and imaging bright stars. Pointing straight up to Polaris and it looks pretty good. Everywhere else and the stars go odd with that spike.

EDIT* I know the focuser protrudes into the light path, that's the nature of the beast with the 130PDS but I never had this problem, it just started random?

Edited January 10, 2021 by Jamgood

[Davey-T]

Bit of flocking come loose ?

Dave

[Jamgood]

Other than that glitch in the optic the collimation is pretty good. 

[Jamgood]

Just now, Davey-T said:

Bit of flocking come loose ?

Dave

It's not flocked. All standard as of now.

[Jamgood]

You can see that the glitch is not even in line with the focuser. It's in a different line. Putting my finger over the scope while de-focused, it is around the top primary mirror clip. Maybe I need to remove the mirror and have a look at it. 

I have looked down with a torch and everything looks normal. No cracks or anything out of place, that I can tell.

[Captain Scarlet]

Have you introduced a heater at all? Could it be a warm air current plume? Also perhaps take a photo with the focuser grossly wound in or out. That will show the whole obstruction-field.

M

[Davey-T]

Does it show up using an eyepiece ?

Dave

[Jamgood]

1 minute ago, Captain Magenta said:

Have you introduced a heater at all? Could it be a warm air current plume? Also perhaps take a photo with the focuser grossly wound in or out. That will show the whole obstruction-field.

M

No, no heater. Nothing had changed at all when it started. I set up in the same place every time, markers on the floor. 

I'll try that now.

1 minute ago, Davey-T said:

Does it show up using an eyepiece ?

Dave

I've never put an eyepiece in this scope. I have the one that came with it but never used it. I can try.

[Jamgood]

Clouds! I'll try again next time I can. Fingers crossed for clear skies. 

Thanks for the help so far guys. 👍