How uncertainties on stellar atmospheric parameters impact exoplanet studies?

TL;DR

This paper investigates how uncertainties in stellar atmospheric parameters, derived from spectroscopic methods, influence the accuracy of exoplanet property estimations, highlighting the importance of precise stellar characterization.

Contribution

It compares two spectroscopic approaches to quantify their impact on stellar and exoplanet parameter uncertainties, emphasizing the significance of method choice.

Findings

Discrepancies between spectroscopic methods significantly affect stellar radius estimates.

Uncertainties in stellar parameters propagate to exoplanet radius and composition estimates.

Method choice can lead to substantial differences in derived planetary properties.

Abstract

Exoplanet properties depend on how well the host star is characterized. For instance, the stellar atmospheric parameters (i.e., effective temperature, surface gravity and overall metallicity) are needed to derive the stellar mass and radius by using evolutionary stellar models or empirical calibrations. I studied how the stellar uncertainties impact the determination of planetary characteristics. By using high-resolution spectra and iSpec, I evaluated how discrepancies between two different spectroscopic approaches (the equivalent method and the synthetic spectral fitting technique) can significantly affect the stellar radius estimation, hence, the exoplanet radius and its possible chemical composition.