File:Carl Friedrich Gauss 1840 by Jensen.jpg
Carl Friedrich Gauss
A Gaussian year is defined as 365.2568983 days.<ref>Template:Cite journal</ref> It was adopted by Carl Friedrich Gauss as the length of the sidereal year in his studies of the dynamics of the Solar System. A slightly different value is now accepted as the length of the sidereal year,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and the value accepted by Gauss is given a special name.
A particle of negligible mass, that orbits a body of 1 solar mass in this period, has a mean axis for its orbit of 1 astronomical unit by definition. The value is derived from Kepler's third law as
- <math>\mbox{1 Gaussian year}= \frac {2\pi} {k} \,</math>
where
- k is the Gaussian gravitational constant.<ref>Template:Cite book</ref>