What is the 'Co-Declination' formula in Celestial Navigation?

The 'Co-Declination' formula in celestial navigation is defined as 90° minus the declination of the celestial body. This is because co-declination represents the angle that measures how far a celestial object is from the celestial equator, with the celestial equator being at 0° declination and the poles being at ±90° declination.

When you subtract the declination from 90°, you effectively derive the co-declination, which aids navigators in converting celestial coordinates into a format that can be used in practical navigation tasks, such as plotting courses or finding the altitude of the star above the horizon during observations.

This formula is foundational for understanding the relationship between the declination of celestial bodies and their positions in the sky relative to the observer's latitude, which is crucial in celestial navigation practices.