Combining Photometry From Kepler and TESS to Improve Short-Period Exoplanet Characterization

TL;DR

This paper presents a Bayesian method to combine Kepler and TESS photometry, enabling better separation of reflected and thermal light in exoplanets, thus improving the accuracy of planetary parameter estimation.

Contribution

The authors develop a novel Bayesian approach for combining multi-band photometry from Kepler and TESS to disentangle planetary reflected and thermal emissions, enhancing exoplanet characterization.

Findings

Simulations show improved constraints on planetary albedo and temperature.

Method effectively separates reflected and thermal light signals.

Applicable to future missions like JWST, CHEOPS, and PLATO.

Abstract

Planets emit thermal radiation and reflect incident light that they recieve from their host stars. As a planet orbits it's host star the photometric variations associated with these two effects produce very similar phase curves. If observed through only a single bandpass this leads to a degeneracy between certain planetary parameters that hinder the precise characterization of such planets. However, observing the same planet through two different bandpasses gives one much more information about the planet. Here, we develop a Bayesian methodology for combining photometry from both \emph{Kepler} and the Transiting Exoplanet Survey Satellite (TESS). In addition, we demonstrate via simulations that one can disentangle the reflected and thermally emitted light from the atmosphere of a hot-Jupiter as well as more precisely constrain both the geometric albedo and dayside temperature of the planet. This methodology can further be employed using various combinations of photometry from the James Webb Space Telescope (JWST), the Characterizing ExOplanet Satellite (CHEOPS), or the PLATO mission.