Modeling the Radial Velocities of HD 240210 with the Genetic Algorithms

TL;DR

This paper introduces the KFIT code, utilizing genetic algorithms for modeling radial velocity data, and demonstrates its effectiveness by confirming a potentially stable two-planet system in HD 240210, possibly the first of its kind in an evolved star.

Contribution

Developed the KFIT code using genetic algorithms for RV data modeling and applied it to confirm a stable 2-planet system in HD 240210 with a 2:1 MMR.

Findings

Confirmed three possible planetary solutions for HD 240210.

Identified a stable two-planet system in 2:1 mean motion resonance.

First potential detection of such MMR in an evolved star system.

Abstract

More than 450 extrasolar planets are known to date. To detect these intriguing objects, many photometric and radial velocity (RV) surveys are in progress. We developed the Keplerian FITting (KFIT) code, to model published and available RV data. KFIT is based on a hybrid, quasi-global optimization technique relying on the Genetic Algorithms and simplex algorithm. Here, we re-analyse the RV data of evolved K3III star HD 240210. We confirm three equally good solutions which might be interpreted as signals of 2-planet systems. Remarkably, one of these best-fits describes the long-term stable two-planet system, involved in the 2:1~mean motion resonance (MMR). It may be the first instance of this strong MMR in a multi-planet system hosted by evolved star, as the 2:1 MMR configurations are already found around a few solar dwarfs.