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Nocturnal: instrument to determine local time using relative positions of two or more stars in the night sky; Octant: measuring instrument used primarily in navigation; type of reflecting instrument; Optical spectrometer, also known as Spectrograph: instrument to measure the properties of visible light; Orrery: mechanical model of the Solar System
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 ...
The frame of a sextant is in the shape of a sector which is approximately 1 ⁄ 6 of a circle (60°), [3] hence its name (sextāns, sextantis is the Latin word for "one sixth"). "). Both smaller and larger instruments are (or were) in use: the octant, quintant (or pentant) and the (doubly reflecting) quadrant [4] span sectors of approximately 1 ⁄ 8 of a circle (45°), 1 ⁄ 5 of a circle (72 ...
A nocturnal is an instrument used to determine the local time based on the position of a star in the night sky relative to the pole star. As a result of the Earth's rotation , any fixed star makes a full revolution around the pole star in 23 hours and 56 minutes and therefore can be used as an hour hand .
An almucantar staff is an instrument chiefly used to determine the time of sunrise and sunset, in order to find the amplitude and consequently the variations of the compass. Usually made of pear tree or boxwood, with an arch of 15° to 30°, [3] it is an example of a backstaff. This is a drawing of an almucantar staff.
Nocturnal used to determine apparent local time by viewing the Polaris and its surrounding stars. Ring dial or astronomical ring used to measure the height of a celestial body above the horizon. It could be used to find the altitude of the Sun or determine local time. It let sunlight shine through a small orifice on the rim of the instrument.
Afrikaans; العربية; Asturianu; Azərbaycanca; বাংলা; Башҡортса; Беларуская; Беларуская (тарашкевіца)
The number used to identify stars in navigation publications and star charts. [Note 2] Common name The name of the star commonly used navigation publications and star charts. Bayer designation: Another name of the star which combines a Greek letter with the possessive form of its constellation's Latin name. Etymology of common name