The discovery of three hot Jupiters, NGTS-23b, 24b, and 25b, and updated parameters for HATS-54b from the Next Generation Transit Survey

ABSTRACT We report the discovery of three new hot Jupiters with Next Generation Transit Survey (NGTS) as well updated parameters for HATS-54b, which was independently discovered by NGTS. NGTS-23b, NGTS-24b, and NGTS-25b have orbital periods 4.076, 3.468, 2.823 d orbit G-, F-, K-type stars, respectively. NGTS-24 HATS-54 appear close to transitioning off main-sequence (if they are not already doing so), therefore interesting targets given observed lack around sub-giant stars. By considering host star luminosities planets’ small separations (0.037–0.050 au), we find that all four above minimum irradiance threshold inflation mechanisms be effective. NGTS-23b has a mass 0.61 MJ radius 1.27 RJ is likely inflated. With 1.21 0.52 MJ, NGTS-24b larger than expected from non-inflated models but its smaller predicted current Bayesian inflationary models. Finally, intermediate between inflated cases, having 0.64 1.02 RJ. The physical processes driving remain poorly understood, building sample can aim identify additional controlling parameters, such metallicity stellar age.