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A diagram of a typical nautical sextant, a tool used in celestial navigation to measure the angle between two objects viewed by means of its optical sight. Celestial navigation, also known as astronavigation, is the practice of position fixing using stars and other celestial bodies that enables a navigator to accurately determine their actual current physical position in space or on the ...
Fifty-seven navigational stars and additionally the star Polaris are given a special status in the field of celestial navigation. Of the approximately six thousand stars visible to the naked eye under optimal conditions, these selected stars are among the brightest and span thirty-eight constellations of the celestial sphere from the ...
Two sample pages of the 2002 Nautical Almanac published by the U.S. Naval Observatory. A nautical almanac is a publication describing the positions of a selection of celestial bodies for the purpose of enabling navigators to use celestial navigation to determine the position of their ship while at sea.
Electronic Navigation, covers the primary means of positioning of the modern navigator. Chapters deal with each of the several electronic methods of navigation, organized by type. Part IV Celestial Navigation, contains techniques, examples and problems and a chapter on sight reduction. Part V
In celestial navigation, lunar distance, also called a lunar, is the angular distance between the Moon and another celestial body. The lunar distances method uses this angle and a nautical almanac to calculate Greenwich time if so desired, or by extension any other time. That calculated time can be used in solving a spherical triangle.
Time sight is a general method for determining longitude by celestial observations using a chronometer; these observations are reduced by solving the navigational triangle for meridian angle and require known values for altitude, latitude, and declination; the meridian angle is converted to local hour angle and compared with Greenwich hour angle.
Gail Godwin: "Celestial Navigation" The New York Times (April 28, 1974). Ms. Godwin writes in 1974, "It is a tribute to the author's gentle genius in preserving the integrity of her people that we do not hate Mary Tell.
A meridian contact is the moment when the object contacts the observer's meridian, i.e. the imaginary line running north–south and through the zenith, nadir, and celestial poles. This is usually done with the equinox Sun at solar noon to determine the observer's latitude, but can be done with any celestial object.