culmination

The moment when a star or other celestial object reaches its maximum altitude above the horizon as the Earth's rotation takes it across the sky. Culmination occurs when the object crosses the observer's meridian. Thus, at culmination an object is either due south or due north of the observer. Circumpolar stars cross the meridian both below and above the pole, events called lower and upper culmination, respectively. "Meridian passage" and "transit" are alternative terms for culmination.