Homogeneous stellar parameters for 717,807 TESS FGK stars using Gaia DR3

Abstract

Precise homogeneous stellar characterisation is crucial for our understanding of the physical properties of exoplanets, their demographics and the environment from which they are formed. We present a homogeneous catalogue of 717,807 TESS FGK dwarfs and early subgiants, making use of isochrones along with Gaia DR3 inputs of photometry, parallax and spectroscopic temperature and metallicity, thus providing one of the largest homogeneous catalogues of stellar ages for TESS stars to date. We determine values for distance, $\log g$, $[\mathrm{M/H}]$, $T_{\mathrm{eff}}$, radius, mass and age. For our best fit values, we calculate absolute median errors of $0.06\,R_\odot$, $0.05\,M_\odot$,$104\,K$ and $2.1\,\mathrm{Gyr}$ on radius, mass, temperature and age respectively. We compare and validate our catalogue values to various literature sources which employ other isochrone grids and asteroseismology. In addition, we identify 278 TESS exoplanet hosts and 915 candidates and recalculate the planet radii for such systems. These homogeneous parameters provide a state-of-the art sample to probe the effect of physical stellar parameters on exoplanet characteristics and architectures.

Figures (9)

• Figure 1: Hertzsprung-Russel diagram for the 755,847 stars used in this study, using Gaia BP-RP colour and absolute G magnitude. To ensure clarity we bin the sample into points and colour code by the log of number of stars in each bin.
• Figure 2: Histogram showing the TESS magnitude distribution of our stellar sample.
• Figure 3: Stellar radius, mass and temperature from this work compared to the TIC radius, mass and temperature. Due to the size of the sample, points are colour coded by the log of the number of stars in each bin. We see good general agreement, with a median residual scatter of 4.43%, 6.94% and 1.79% for radius, mass and temperature respectively. The dashed line represents the 1:1 line.
• Figure 4: Stellar radius (left), mass (middle) and temperature (right) we fit with our methodology compared to the Berger_2023 (top), SWEET-Cat (middle) and NASA exoplanet archive (bottom) catalogues. We only take systems from the NASA exoplanet archive with a radius and mass precision greater than 20%. The 1:1 line is represented by the dashed line. We calculate a median residual scatter of 2.76%, 3.77% and 1.30% in radius, mass and temperature respectively for our comparison to the Berger_2023 catalogue, 5.00%, 4.82% and 1.17% for SWEET-Cat and 3.51%, 4.17% and 1.23% for NASA exoplanet archive systems.
• Figure 5: Values of stellar radius (left), mass(middle) and temperature (right) we derive with our methodology compared to overlapping stars in the Kepler LEGACY survey. We plot stars with discrepant metallicity between Gaia and LEGACY values in grey ($\Delta_{\textnormal{met}} > 0.2$). We calculate a median residual scatter of 3.49%, 2.46% and 0.95% on radius, mass and temperature respectively. The dotted line represents the 1:1 line.