Polar star position?

[maub]

Hopefully someone can clear up some of my confusion regarding the position of the Polar star during polar alignment. I have used three methods to determine the position on the star in the polar scope. These are: the stand alone program Polar Finder, EQMOD’s Polar Scope and the handset readout from my SynScan handset. The position on Polar finder is slightly (bu noticably) further advanced, in time, compared to EQMOD and the EQMOD and SynScan position values also do not match. Earlier today, a comparison showed a position of 23:24 from EQMOD compared to 23:39 from SynScan. I have double checked the date, time and position. Any ideas on the reason for the differences, or am I doing something wrong?

[g0ibi]

A I understand it, as long as Polaris is on the circle and somewhere near the time its fine and will track without a problem!

[chrisshillito]

The synscan hour angle is always slightly wrong as it doesn't take into account precession (EQMOD & Polarfinder both do). If your getting a difference between EQMOD & Polarfinder then check you have the observing location set precisely the same in both applications.

Chris.

[maub]

Thanks for the explanation. I have re-checked the location and still get a slight, but noticable, difference between Polar Finder and EQMOD.

Thanks for EQMOD - great program.