Efficient fitting of multiplanet Keplerian models to radial velocity and astrometry data

Abstract

We describe a technique for solving for the orbital elements of multiple planets from radial velocity (RV) and/or astrometric data taken with 1 m/s and microarcsecond precision, appropriate for efforts to detect Earth-massed planets in their stars' habitable zones, such as NASA's proposed Space Interferometry Mission. We include details of calculating analytic derivatives for use in the Levenberg-Marquardt (LM) algorithm for the problems of fitting RV and astrometric data separately and jointly. We also explicate the general method of separating the linear and nonlinear components of a model fit in the context of an LM fit, show how explicit derivatives can be calculated in such a model, and demonstrate the speed up and convergence improvements of such a scheme in the case of a five-planet fit to published radial velocity data for 55 Cnc.

ApJS accepted

References in corpus (3)

• Four New Exoplanets and Hints of Additional Substellar Companions to Exoplanet Host Stars
• Double-blind test program for astrometric planet detection with Gaia
• Astrometric Detection of exo-Earths in the Presence of Stellar Noise

Cited by in corpus (1)

• A Third Planet Orbiting HIP 14810