This page describes a method to fine tune your polar alignment if you
have a 'GOTO' capable mount.

Identify three stars near the celestial equator seperated by 45 degrees
or more from your local meridian. There should be a star E, near, and W of your meridian.
Goto and sync on the star near the meridian.
Slew to the SE of the E star, then GOTO the E star.
Record the position of the star in your eyepiece or by other means
Then slew to the SE of the M(eridian) star and then GOTO the M star
Record the position of the star in your eyepiece or by other means
And finally slew SE of the W star then GOTO the star. Record the position of the star in your eyepiece or by other means

Ideally the record position should be one on top of the other.
Second best to ideal is the stars form a line with no DEC component.
If the stars do not form a line without a DEC component but do form
a semi-straight line tilted to the left or right then adjust the AZ of the wedge/mount.
If there is a 'hump' in the line with the M star high or low then adjust
the ALT of the mount.

Repeat as necessary till you get a nice tight group or straight line with as
little tilt and hump as possible within the mechanical contraints of your mount.

I use Skymap Pro to pick the stars.
The M star is then centered and the programs 'sync on star' funtion is used.
All subsequent slews and goto are then done from the computer.



The following images were shot in twilight, each frame comprised of three
seperate images stacked without registration.
Critical focusing was not done (understatment!)

Here is an example of a mount needing an AZ adjustment with a calculated
drift of 1 arcsec in 3.4 minutes time.


Here is the same mount after tweaking the AZ, calculated drift is now
approx 1 arcsec in 15 minutes time.

Noticed the elapsed real time - 5-6 minutes or so.