Stars for iterative polar alignment?
Posted 29 March 2009 - 11:35 AM
What stars do you use for iterative polar alignment?
I saw somewhere that it should be more than 3h away in RA, but what about dec? Could, say, any of the other stars in Ursa Minor be use (e.g. Kochab)?
Posted 29 March 2009 - 01:09 PM
The 2nd says 90 deg. from polaris in Dec, so this method is a no-go for me
Have anyone tried it with a star like 45 deg. from polaris?
Posted 29 March 2009 - 05:05 PM
The reason for using stars near the equator is to make the alignment process more sensitive to error. This is true for both drift and iterative alignment.
Posted 30 March 2009 - 01:35 AM
Posted 30 March 2009 - 01:11 PM
If need be, pick what star you can, just don't take out too much offset ( I know how tempting it is to try to take out most of a large error; don't do it!) and you should converge. Maybe take out only half the error, not 3/4 or more. It might take several cycles though; be patient.
Posted 30 March 2009 - 03:22 PM
I'll try it the next time out. Thank you for your help
Posted 30 March 2009 - 03:42 PM
Posted 31 March 2009 - 02:15 AM
I do the same, but sometimes the pol-scope is out of alignment since I move my mount a lot. It would be nice to easily be able to spend like 5 min to correct for this possibility.