Gaussian gravitational constant

Carl Friedrich Gauss expressed the gravitational constant in units of the solar system from, rather than the usual in the laboratory or in everyday life common units (now SI base units). This has the advantage that the motion of the planets in the solar system can be calculated without needing to know the value of the astronomical unit in meters or the mass of the sun and the planets in kilograms. The Gaussian gravitational constant k is represented by the symbols.

As used Gaussian units:

• Length A: Astronomical unit
• Time D: sunny day (mean duration of a rotation of the earth )
• Mass S: mass of the Sun

From the third Kepler 's law as applied to the motion of the earth, he calculated the value of the Gaussian gravitational constant, which is calculated as 2π / ( length of a year in days). 1939, the value was

By the International Astronomical Union ( IAU) defined as a defining constant of astronomy.

The law of gravity is then

Where all quantities are indicated with a tilde now in the units listed above. Note that the constant squared enters into force law.

2012, the IAU decided to remove the Gaussian gravitational constant from the system of astronomical constants and define the formerly derived from their astronomical unit new.