Using Asteroseismology to Calibrate the Physical Parameters of Confirmed Exoplanets and Their Evolved Host Stars

Abstract

Asteroseismology offers a profound window into stellar interiors and has emerged as a pivotal technique in exoplanetary research. This study harnesses the Transiting Exoplanet Survey Satellite observations to reveal, for the first time, the asteroseismic oscillations of four exoplanet-hosting stars. Through meticulous analysis, we extracted their asteroseismic signatures, enabling the precise determination of stellar masses, radii, luminosities, and surface gravities. These parameters exhibit markedly reduced uncertainties compared to those derived from spectroscopic methods. Crucially, the exoplanets orbiting these stars were initially identified via radial velocity measurements. The refinement of host stellar masses necessitates a corresponding adjustment in planetary characteristics. Employing asteroseismology, we recalibrated the exoplanets’ minimum masses and semimajor axes—a novel approach in the field. For instance, the exoplanet HD 5608 b's minimum mass, denoted as $M\sin i$ , was ascertained to be 1.421 ± 0.091 M _J through the integration of asteroseismic and radial velocity data. Similarly, two planets within the 7 CMa system yielded $M\sin i$ values of 1.940 ± 0.064 M _J and 0.912 ± 0.067 M _J , respectively. Two planets in the HD 33844 system presented $M\sin i$ figures of 1.726 ± 0.145 M _J and 1.541 ± 0.182 M _J , while the HIP 67851 system's planets registered $M\sin i$ at 1.243 ± 0.139 M _J and a notably higher 5.387 ± 0.699 M _J . This investigation extends beyond mere parameter refinement, it underscores the synergy between asteroseismology and exoplanetology, yielding unprecedented precision in system metrics. Focusing on a quartet of K-type giants in advanced evolutionary phases, our work positions these systems as invaluable astrophysical laboratories, offering insights into the potential trajectory of our own solar system's fate.

Keywords

• Exoplanets
• Asteroseismology
• Planet hosting stars
• Evolved stars