The first complication applies to all celestial objects: the object's declination equals the observer's astronomical latitude, but the term "latitude" ordinarily means geodetic latitude, which is the latitude on maps and GPS devices. In the continental United States and surrounding area, the difference (the vertical deflection) is typically a few arcseconds (1 arcsecond = of a degree) but can be as great as 41 arcseconds.
The first complication applies to all celestial objects: the object's declination equals the observer's astronomical latitude, but the term "latitude" ordinarily means geodetic latitude, which is the latitude on maps and GPS devices. In the continental United States and surrounding area, the di!fference (the vertical deflection) is typically a few arcseconds (1 arcsecond = of a degree) but can be as great as 41 arcseconds.