I’m trying to understand the relationship of horizontal coordinates (altitude, azimuth) and the celestial coordinate system. One thing I’d not appreciated is the altitude of Polaris, the north star, is pretty much always at a fixed elevation. Its Declination is 89° 15′ 50.8″, or about 90° (at the celestial north pole). And at my house at 39.2°N it’s pretty much always at altitude 39.2° above the horizon. I guess that sort of makes sense, it’s the only way it makes sense as a North Star, but I’d never really noticed it before and naively thought Polaris’ elevation would change with the seasons. Maybe because its at the tip of the little Dipper which does rotate with the seasons, and when the bowl is higher in the sky it feels like Polaris is too.
This makes determining your latitude in the northern hemisphere pretty easy; just site the north star and measure its angle from the horizon. Preferably in calm seas with clear skies.