A star which guides mariners at sea. Obsolete.

any of various bright stars formerly used to determine terrestrial longitude on the basis of their relative position with respect to that of the moon.

each of a group of 46 stars visible from Greenwich, whose positions are tabulated and used for computations such as the determination of longitude.

a star whose geocentric distance from the moon is given in the Nautical Almanac for certain hours, so that the longitude may be found from them.

A star which culminates at almost the same time and declination as the moon.

any of various bright stars by which sailors can navigate.