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lineout
09-01-2015, 12:13 PM
Hi all,

Would like to pick the communities brain.

I recently purchased a Sky Watcher Star Adeventurer and was wondering if anyone could give me some instructions on how to polar align it.

I had a go the other night without much luck.

Regards

LewisM
09-01-2015, 01:34 PM
Good quality compass with local declination subtracted.

For instance, for me my mag declination is 11 degrees, so for the compass to point true south subtract 11 degrees from 180, giving true south at 169 degrees

clive milne
09-01-2015, 02:35 PM
The following procedure will get you pretty close:
Find your exact longitude and latitude.
Plug those numbers (and the date) into the the solar noon calculator here; http://www.esrl.noaa.gov/gmd/grad/solcalc/
Place a ladder a couple of feet due north of where you want to set up your telescope.
Suspend a plumb bob from the top of the ladder. (if it is windy, a container of water should be placed on the ground, with the weight being in the water and not touching the container sides)
At solar noon, the shadow of the string on the ground will point due south.
For a shadow 57.3cm long, 1mm accuracy means you will be within 6 arc minutes of the true pole.

graham.hobart
09-01-2015, 02:38 PM
Hi mate, welcome, Lewis forgot to mention that your equatorial mount (if it is) should also be set at your latitude in degress bearing in mind most mounts actual latitude scales are not that accurate.
Have you seen or googled drift alignment>?
Do you have the EQ wedge and polar scope? if not it could be quite difficult to polar align without the wedge as this is where the latitude is set.
For example- where I am in Tas is 42' South roughly so I am set up at 42' on the scale roughly (to start with at least) and my magnetic variance from true south is about 11' so I am a bit to the west of true south. In truth because my compass is affected by all the metal around and my latitude scale is not that accurate, I have to then adjust the alignment with another method-(drift/software etc) to get it good enough to photograph with.
There is a bunch of stuff on line about polar aligning an equatorial mount-maybe even some stuff in the articles section on ICE IN SPACE - using compasses (iphone?) and spirit levels etc.
If you are using a computer to run a camera you can download different software that helps you align (PHD 2/ Pole Align Max/ Alignmaster/ etc)
Hope you get it sorted-its the hardest part when you first start to image objects but worth doing well.
Good luck
Graham

graham.hobart
09-01-2015, 02:41 PM
I will also vouch for the solar noon method- when I had a portable mount set up I used this and marked lines on the decking so help me at night. Works very well, Then you just have to fiddle with your latitude!:thumbsup:

lineout
09-01-2015, 05:41 PM
Thanks for all the advice guys.

I hadn't taken into account magnetic south vs true south.

Also thank you to graham.hobart for the suggestions.

If the weather clears in Sydney. I'll give it another go.

beren
09-01-2015, 08:12 PM
You could make this Jig (http://www.iceinspace.com.au/index.php?id=63,499,0,0,1,0) to get close. The Star Adventurer looks like a cool bit of gear I brought the eq head separately to work with little portable mount I own.
Are you trying to polar align with the polar scope or drift aligning ? Checking the manual the polar scope looks like it has to be calibrated to the RA axis and then adjust alt/az {not much free play with the azimuth on the eq head}controls to get the pattern provided with the polar scope to match the asterism sigma octanis is in . Can be tricky if your not familiar with finding the SCP. I'd plan spending a few hours getting the mount drift aligned and marking the surface where your tripod stands and checking the view through the polar scope to get accustomed to that area of sky {can also check your compass etc}.