Equipment for determining double star PA

[lone77star]

I'm looking to get a new scope, soon, to do some serious double star observations.

Does anyone know about equipment to determine position angle? Some of the catalogs have entries that go back several decades, but nothing newer. Such an attachment would help greatly.

Thanks!

[Merlin66]

I used a 8" perspex 360 degree protractor, drilled to sit on my favourite eyepiece. You can easily determine the E-W from the star drift and hence N-S.
A fixed pointer on the focuser showed the position angle.
(I eventually added an iceland spar crystal to assist in distance measurement.) Nowadays there are software programs which can be used (even with webcams) to accurately measure position angle and distances.
HTH

[lone77star]

Awesome, Merlin. That helps a lot. :D

[Saturnine]

Hi Carl

There are a few other methods for measuring P.A. and Seperation of double and multiple stars, one is with an Filar Micrometer, which are expensive and possibly hard to get and another way is with an Illuminated Astrometric Reticle Eyepiece, the more readily available models are from Meade and Celestron and are reasonably priced. I can also recommend a good book on all things to do with double stars , Observing and Measuring Visual Double Stars by Bob Argyle, published by Springer, got mine through Amazon at a good price.
I'm sure there are other double star observers out there that can impart their knowledge and techniques of all things binary. Enjoy the journey.

Jeff