2024/08/30 by Ben Cassese, Justin Vega, Tiger Lu +3 · 1 voice · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Scientific Research and Discoveries #Stellar, planetary, and galactic studies #astro-ph.EP #astro-ph.IM
paper · pdf · doi:10.21105/joss.06972
openalex publication_date 2024/08/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
While astronomers often assume that exoplanets are perfect spheres when analyzing observations, the subset of these distant worlds that are subject to strong tidal forces and/or rapid rotations are expected to be distinctly ellipsoidal or even triaxial.Since a planet's response to these forces is determined in part by its interior structure, measurements of an exoplanet's deviations from spherical symmetry can lead to powerful insights into its composition and surrounding environment.These shape deformations will imprint themselves on a planet's phase curve and transit lightcurve and cause small (1s-100s of parts per million) deviations from their spherical-planet counterparts.Until recently, these deviations were undetectable in typical real-world datasets due to limitations in photometric precision.Now, however, current and soon-to-come-online facilities such as JWST will routinely deliver observations that warrant the consideration of more complex models.To this end we present squishyplanet, a JAX-based Python package that implements an extension of the polynomial limb-darkened transit model presented in Agol et al. (2020) to non-spherical (triaxial) planets, as well as routines for modeling reflection and emission phase curves.