If `alpha`, H, A and `delta` be the altitude, hour angle, azimuth and declination of a circumpolar star at its elongation, in latitude`lambda` the following relation holds good
If`delta`is the declination of the star and `phi` is the latitude of the observer then the hour angle of the star at elongation is given by
The latitude (`lambda`) of a place and the altitude (`alpha`) of the pole are related by
The parallax equation ` Delta P = (Bm Delta h)/(H - h)` is applicable to entire overlap of the photographs only if parallax is measured