Abstract.We compare numerical efficiency of the two kinds of series for the first-order intermediate orbit for general planetary theory: (1) the classical expansion involving mean longitudes of the planets; (2) an expansion resulting from the theory of elliptic functions. We conclude that mutual perturbations of close couples of planets (the ratio of major semi-axes ~ 1) can be represented in more compact form with the aid of the second kind of series.
Two kinds of series for the first-order intermediaryIn spite of significant progress of numerical approaches to construct the theories of motion of the major planets, analytical theory of planetary motion remains to be a challenging and interesting scientific task. Recently the interest in constructing analytical planetary theories has been revived by the idea to use an elliptic function of time (instead of time itself) as independent variable in order to make the resulting series more compact (see, Brumberg (1996) and references therein). Our aim is to compare the numerical efficiency of the classical series involving mean longitudes of planets and the series resulting from the application of elliptic functions for the particular case of the first-order intermediate orbit for general planetary theory (Brumberg, 1994