Lever héliaque d’un astre is a French watch term that refers to the sun’s heliacal rising. This is the phenomenon of the sun reappearing in the sky after it has been invisible for a period of time due to its position in the sky. The term specifically refers to the time when the sun begins to reappear in the morning sky, signaling the start of a new day. This phenomenon can be used to track the passage of time, as it marks the beginning of a new day, and it can be used to set the time of clocks and watches.
