SWEET-Cat: A view on the planetary mass-radius relation

¹ Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal
² Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
³ Instituto de Alta Investigación, Universidad de Tarapacá, Casilla 7D, Arica, Chile
⁴ Aix Marseille Univ, CNRS, CNES, LAM, Marseille, France
⁵ Instituto de Astrofísica de Canarias, 38200 La Laguna, Tenerife, Spain
⁶ School of Physics & Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
⁷ INAF – Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy

^★ Corresponding author; sergio.sousa@astro.up.pt

Received: 29 July 2024
Accepted: 16 September 2024

Abstract

Aims. SWEET-Cat (Stars With ExoplanETs Catalog) was originally introduced in 2013, and since then, the number of confirmed exoplanets has increased significantly. A crucial step for a comprehensive understanding of these new worlds is the precise and homogeneous characterization of their host stars.

Methods. We used a large number of high-resolution spectra to continue the addition of new stellar parameters for planet-hosting stars in SWEET-Cat following the new detection of exoplanets listed both in the Extrasolar Planets Encyclopedia and in the NASA exoplanet archive. We obtained high-resolution spectra for a significant number of these planet-hosting stars, either observed by our team or collected through public archives. For FGK stars, the spectroscopic stellar parameters were derived for the spectra following the same homogeneous process using ARES+MOOG as for the previous SWEET-Cat releases. The stellar properties were combined with the planet properties to study possible correlations that could shed more light on the star-planet connection studies.

Results. We have increased the number of stars with homogeneous parameters by 232 (~25% – from 959 to 1191). We focus on the exoplanets that have had both mass and radius determined to review the mass-radius relation, and we find results consistent with the ones previously reported in the literature. For the massive planets, we also revisit the radius anomaly, confirming a metallicity correlation for the radius anomaly already hinted at in previous results.