1) Major celebrities 
Leading lights (also known as range lights in the United States) are a pair of light beacons, used in navigation to indicate a safe passage for vessels entering a shallow or dangerous channel; and may also be used for position fixing. At night, the lights are a form of leading line that can be used for safe navigation. The beacons consist of two l...
two or more signal lights positioned to indicate a leading line, or navigational course, in the direction in which they may be seen in vertical alignment