On the contrary, an object reaches its lowest position when passing through the semi-circle which includes the nadir and the nearest celestial pole, and this phenomenon is called lower culmination.

• 经过包括天顶的那半个子午圈时,天体到达最高位置,称为上中天。经过包括天底的那半个子午圈时,天体到达最低位置,称为下中天。