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Declination (Dec) is a celestial coordinate that measures the angular distance of an object north or south of the celestial equator. It is the celestial equivalent of latitude on Earth and is measured in degrees, minutes, and seconds. Declination is used with Right Ascension to find the location of celestial objects in the sky.

Polaris is a star located nearly at the north celestial pole, making it an excellent fixed point for navigation in the Northern Hemisphere. It is very close to the point in the sky around which all the northern stars appear to revolve. The angle of Polaris above the horizon closely corresponds to the observer's latitude in the Northern Hemisphere.

Altitude in celestial navigation is the angle from the observer's local horizon up to a celestial body. It is measured in degrees from 0 at the horizon to 90 at the zenith (directly overhead), and it helps navigators determine their latitude or how to steer a course.

The Celestial Equator is an imaginary line that extends the Earth's equator into space. It divides the celestial sphere into the northern and southern hemispheres and is used as a reference plane for the equatorial coordinate system. Navigators can use it to determine an object's declination.

Right Ascension (RA) is a celestial coordinate used to measure the longitudinal position of objects in the sky. It is analogous to longitude on Earth but is measured in hours, minutes, and seconds. RA is used in conjunction with Declination to pinpoint the location of celestial objects.

A sextant is a navigational instrument used to measure the altitude of celestial bodies above the horizon. This measurement can determine the observer's latitude and longitude. The angle measured with a sextant is often used in conjunction with tables to calculate one's position at sea.

Azimuth is a navigational term that refers to the angle measured clockwise from a specific reference direction (usually true north) to the point where a vertical line from a celestial body intersects the horizon. It defines the direction to an object and is used in both celestial and terrestrial navigation.