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

2009/04/24 by J. T. Wright, A. W. Howard · 1 citation
Physics and Astronomy · #astro-ph.SR

paper · pdf · doi:10.1088/0067-0049/182/1/205

ApJS accepted

arxiv created 2009/04/24 · arxiv updated 2009/12/01

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.

Cited by

• Sub-stellar companions of the young weak-line TTauri Star DoAr21

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