SOAP-T: A tool to study the light-curve and radial velocity of a system with a transiting planet and a rotating spotted star

TL;DR

SOAP-T is an enhanced computational tool designed to simulate light-curves and radial velocity signals for systems with transiting planets around spotted, rotating stars, aiding in the analysis of stellar activity and planetary parameters.

Contribution

This paper introduces SOAP-T, an improved version of SOAP, capable of modeling complex star-planet interactions including star spots and transit anomalies, validated against real data.

Findings

SOAP-T accurately reproduces observed light-curves and radial velocities.

The tool effectively models transit anomalies caused by star spots.

Application to HAT-P-11 demonstrates its utility in real systems.

Abstract

We present an improved version of SOAP (Boisse et al. 2012) named "SOAP-T", which can generate the radial velocity variations and light-curves for systems consisting of a rotating spotted star with a transiting planet. This tool can be used to study the anomalies inside transit light-curves and the Rossiter-McLaughlin effect, to better constrain the orbital configuration and properties of planetary systems and active zones of their host stars. Tests of the code are presented to illustrate its performance and to validate its capability when compared with analytical models and real data. Finally, we apply SOAP-T to the active star, HAT-P-11, observed by the NASA Kepler space telescope and use this system to discuss the capability of this tool in analyzing light-curves for the cases where the transiting planet overlaps with the star's spots.