orbitN

orbitN is a second order symplectic integrator developed with the primary goal of generating accurate and reproducible long-term orbital solutions for near-Keplerian planetary systems with a dominant mass M0. Among other features, orbitN includes M0's quadrupole moment, a lunar contribution, and post-Newtonian corrections (1PN) due to M0 (fast symplectic implementation). To reduce numerical roundoff errors, orbitN features Kahan compensated summation. orbitN version 1.0 focuses on hierarchical systems without lose encounters but can be extended to include additional features in future versions. orbitN version 1.0 uses Gaussian units, i.e., length, time, and mass are expressed in units of au, days, and fractions of M0.