Horizontal line across bright stars

[Grumman]

Hello,

Lately I have noticed that I am getting a horizontal line across bright stars in my photos.

This is not the case with all the subs... 

I can be 30minutes down the sequence and then couple of subs will have those lines across bright stars and then they go away...

I have attached some examples - any Idea what might be causing this?

 

Equipment used:

Sky-Watcher 72ED

Sky-Watcher 0.85x FF-FR

Canon EOS 100D non-modified

Astronomik CLS-CCD Filter

 

Regards,

Thanasis

 

[SyedT]

When this happens to me it's usually due to passing cloud. 

[geordie85]

I usually get this if there is an electrical/ telephone wire in my FOV 

[Grumman]

Thank you @SyedT & @geordie85 for your replies!

Funny enough now that you mentioned it, there were 3 overhead electrical wires when I took those shots as they were taken the same night from the same spot...

Thanks a lot !

[Alien 13]

Washing lines or even a thread of spider silk can do it too.

Alan