The best analysis done for the ensemble of kepler and tess planets to date assumes all planets are circular and derives the more fundamental parameters like the planet radius using the stellar…

This $1,076,775 federal grant award to President and Fellows of Harvard College, also known as Harvard University, funds research to enhance the accuracy and precision of planetary parameters derived from transit photometry data. The research leverages the ExoFastV2 global modeling approach to simultaneously constrain planet eccentricity without the need for radial velocity measurements, addressing biases in prior methods that assumed circular orbits. This work is expected to improve fundamental inferences about exoplanet occurrence rates and other key properties. The grant is awarded by the Shared Services Center, a civilian federal agency, and the performance will take place at Harvard's campus in Cambridge, Massachusetts. The award does not have a set-aside designation, as Harvard is a large, prestigious research institution with substantial federal research and development capabilities across diverse scientific disciplines.

The best analysis done for the ensemble of kepler and tess planets to date assumes all planets are circular and derives the more fundamental parameters like the planet radius using the stellar properties calculated separately. This method is internally inconsistent, resulting in biased planetary parameters and a discrepancy between the stellar density implied by the transit and the stellar density measured from the star. The majority of ED exoplanets have since been statistically validated without radial velocities, meaning the planet parameters biased by an assumed circular orbit are currently the definitive reference for the majority of ED exoplanets. This bias most directly impacts the scaled semi-major axis, which feeds directly into the most fundamental inferences about planets, like planet occurrence rates. EXOFASTV2, which simultaneously models the transit light curve, a spectral energy distribution, and a stellar evolutionary track while using kepler's law to ensure the model parameters are self consistent, is capable of measuring a precise eccentricity using nothing but the transit photometry and catalog data that is already available for essentially all transiting exoplanet candidates, now and in the foreseeable future. We demonstrate that we can use such a global model to constrain the eccentricity without radial velocities that is remarkably precise and perfectly consistent with the result from radial velocities. Further, we show that even in the low signal to noise regime of an earth-sized planet, the method still provides a meaningful eccentricity constraint and yields more accurate and more precise planetary parameters free from the bias of an assumed circular orbit.