Numerical Nonadiabatic Tidal Calculations with <tt>GYRE-tides</tt> : The WASP-12 Test Case

Abstract We revisit the tidal evolution of the WASP-12 system using direct numerical calculations with the GYRE-tides code. WASP-12b is a hot Jupiter on a 1.1 day orbit around a slightly evolved F-type star. Its observed orbital decay rate, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo stretchy="false">∣</mml:mo> <mml:msub> <mml:mrow> <mml:mover accent="true"> <mml:mrow> <mml:mi>P</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>̇</mml:mo> </mml:mrow> </mml:mover> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">orb</mml:mi> </mml:mrow> </mml:msub> <mml:mo>/</mml:mo> <mml:msub> <mml:mrow> <mml:mi>P</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">orb</mml:mi> </mml:mrow> </mml:msub> <mml:mo stretchy="false">∣</mml:mo> <mml:mo>≈</mml:mo> <mml:mn>3.2</mml:mn> <mml:mspace width="0.25em"/> <mml:msup> <mml:mrow> <mml:mi mathvariant="normal">Myr</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> , provides a strong constraint on stellar tidal dissipation. We confirm that linear tides with radiative damping and convective damping, as currently implemented, are not sufficient to reproduce the observed inspiral timescale. Nevertheless, our calculations, based on fully nonadiabatic forced oscillations in MESA stellar models with convective envelopes, yield dissipation rates that are consistent with previous semianalytic and adiabatic estimates, confirming the robustness of our numerical framework. As the only open-source, actively maintained tool that calculates the full nonadiabatic, mode resolved linear tidal response of the star, GYRE-tides provides a benchmark calculation for WASP-12 and future applications. Our results validate GYRE-tides as a tool for analyzing combined radiative and convective damping, and indicate that the observed decay rate requires tidal dissipation operating in or near the fully damped regime, which may be achieved through nonlinear damping. These contributions could also be evaluated by computing the wave luminosity at the radiative–convective boundary using our tool. GYRE-tides offers an open-source framework for computing tidal dissipation in short-period exoplanet systems, including the many systems expected to show orbital decay in upcoming Roman surveys.