How do I do a polar alignment id I can see the celestial south pole from my location?

[White Rabbit]

Hi

I have a ETX125 and the tracking on it leaves a lot to be desired. So I'd like to do a polar alignment but have never really bothered with it because the south pole is obscured by trees and a house.

I have a compass but that only tells me where south is that enough for polar alignment after I set the wedge to the right degree for latitude?

Thanks

[[1ponders] (Paul)]

Are you considering doing some DSO imaging with your setup? If you aren't why do you need to put the scope on a wedge?

If you are going to do some imaging (or just want to use the wedge) then the best way for you to polar align would be to drift align it. For visual work only though you could get away with adjusting your altitude by cutting a triangular board with the narrow angle the same as your latitude, rest the longest side against the plate of the wedge and put a level on the top. Once you are level your wedge should be set close enough to latitude for you to do visual observing. For you azimuth adjustment, find out the magnetic deviation for Sydney and subtract or add (as needed) to your magnetic south reading of the compass.

[madwayne (Wayne)]

12 degrees East of South will get you near enough for Sydney.

[dannat (Daniel)]

there is a really good article on this in the Projects/Articles section in the left tab. You might also look at a a map showing the magnetic/true south variance.
daniel

[citivolus (Ric)]

Don't feel like you are that disadvantaged - even those of us with a clear southern view can't see the SCP Some days I miss Polaris! I could do a polar alignment in daylight with a DSLR.

[OneOfOne (Trevor)]

Originally Posted by madwayne

12 degrees East of South will get you near enough for Sydney.

Yep! So face south with the compass in your hand. True south will be 12 degrees to your left. Set the scope to point at that angle and you will be set.

[asterisk (Geoff)]

Originally Posted by White Rabbit

Hi

I have a ETX125 and the tracking on it leaves a lot to be desired. So I'd like to do a polar alignment but have never really bothered with it because the south pole is obscured by trees and a house.

I have a compass but that only tells me where south is that enough for polar alignment after I set the wedge to the right degree for latitude?

Thanks

With my Goto mount, when I can't see Octans (all the time in my backyard), I set the mount up with a compass as mentioned, enter latitude, longitude, time and do an alignment without using actual stars - let the mount's computer determine the location of stellar objects.

I then pick a southern star that I can see (Rigil Kentaurus, Acrux, etc) send the scope to it, turn on my laser which is on the scope and adjust the azimuth and altitude until the laser is on the star. The mount is then polar aligned.

You can fine tune with drift alignment for imaging, if required. I then do a full 2 star alignment with calibration stars so that the mount's computer knows where it is.

[White Rabbit]

Thanks gys I'll give the suggestions a go.