sinusoidal satellite trails.

[woodblock]

Some time ago I posted a problem I had with slightly elongated stars. A characteristic of this was that satellite trails across a frame showed a distinct and very even sinusoidal path. To cut a long story short I've now discovered that it was caused by a slight vibration which was due to some of the screws on the mount and telescope being slightly loose.

 

The scope is a Newtonian and the first problem was that one of the locking screws on the mirror was loose. I found this while adjusting the collimation.

 

The second problem was one of the grub screws holding the mounting plate on which the dovetail bar sits was also slightly loose. I had previously fitted a new, wider mounting plate.

Anyway the moral is "Keep your screws and bolts tight".

 

Cheers

Steve

 

 

[woodblock]

For future reference this is what my satellite trail looked like in case someone ever has the same problem.