abstract:The Gaussian gravitational constant (symbol k) is an astronomical constant first proposed by German polymath Carl Friedrich Gauss in his 1809 work Theoria motus corporum coelestium in sectionibus conicis solem ambientum ("Theory of Motion of the Celestial Bodies Moving in Conic Sections around the Sun"), although he had already used the concept to great success in predicting the orbit of Ceres in 1801. It is equal to the square root of GM where G is the Newtonian gravitational constant and M is the solar mass and roughly equal to the mean angular velocity of the Earth in orbit around the Sun.