Speaker
Description
Accurate stellar parameters are essential for interpreting exoplanetary systems and, in particular, for exploiting the atmospheric survey that will be carried out by ESA’s Ariel mission. Ariel will observe the atmospheres of roughly one thousand exoplanets using a tiered survey strategy, and requires a precise and homogeneous characterisation of host stars across a broad parameter range before launch in 2029. Previous Ariel stellar characterisation efforts have focused on FGK-type stars; methods optimised for these cooler stars are not directly applicable to hotter, rapidly rotating A–F stars because of severe line broadening and blending.
This work presents a uniform determination of fundamental parameters for 18 hot stars (6800 K ≲ Teff ≲ 9560 K) in the Ariel Tier 1 Mission Candidate Sample, all hosting close-in giant planets.
The new sample occupies the upper main sequence (M⋆ ≈ 1.4–2.3 M⊙) and exhibits thin‑disc kinematics and predominantly solar or super‑solar metallicities. Combining these results with previous FGK analyses demonstrates that correlations between stellar mass, metallicity, and planetary density and radius identified for solar‑type stars also extend into the A–F regime, reinforcing the role of host-star properties in shaping close-in giant planets.