An Etymological Dictionary of Astronomy and Astrophysics
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The coupling constant appearing in → Einstein's field equations, expressed by: κ = 8πG/c⁴, where G is the Newtonian → gravitational constant and c the → speed of light.

→ einstein; → gravitational; → constant.

The constant, denoted k, defining the astronomical system of units of length (→ astronomical unit), mass (→ solar mass), and time (→ day), by means of → Kepler's third law. The dimensions of k² are those of Newton's constant of gravitation: L ³M ^-1T ^-2. Its value is: k = 0.01720209895.

→ Gaussian; → gravitational; → constant.

A fundamental constant that appears in → Newton's law of gravitation. It is the force of attraction between two bodies of unit mass separated by unit distance: G = 6.673 x 10^-8 dyn cm² g^-2 or 6.673 x 10^-8 cm³s^-2g^-1, or 6.673 x 10^-11 N m² kg^-2 or 6.673 x 10^-11 m³s^-2kg^-1. It was first measured in 1798 by Henry Cavendish (1731-1810), 71 years after Newton's death. Same as the → Newtonian constant of gravitation.

→ gravitational; → constant.

A parameter representing the product of the → gravitational constant by the → solar mass. It is 13.27 x 10¹⁹ m³ s^-2.

→ heliocentric; → gravitational; → constant.

A parameter representing the product of the → gravitational constant by the → lunar mass. It is 49.03 x 10¹¹ m³ s^-2.

→ selenocentric; → gravitational; → constant.

A parameter representing the product of the → gravitational constant by the Earth's mass. It is 3.987 x 10¹⁴ m³s^-2 or 3.987 x 10⁵ km³s^-2.

→ terrestrial; → gravitational; → constant.