HATS-25b through HATS-30b: A Half-dozen New Inflated Transiting Hot Jupiters

HATS-25b through HATS-30b: A Half-dozen New Inflated Transiting Hot Jupiters from the HATSouth Survey

Authors:

Espinoza et al

Abstract:

We report six new inflated hot Jupiters (HATS-25b through HATS-30b) discovered using the HATSouth global network of automated telescopes. The planets orbit stars with V magnitudes in the range ∼12−14 and have masses in the largely populated 0.5MJ−0.7MJ region of parameter space but span a wide variety of radii, from 1.17RJ to 1.75RJ. HATS-25b, HATS-28b, HATS-29b and HATS-30b are typical inflated hot Jupiters (Rp=1.17−1.26RJ) orbiting G-type stars in short period (P=3.2−4.6 days) orbits. However, HATS-26b (Rp=1.75RJ, P=3.3024 days) and HATS-27b (Rp=1.50RJ, P=4.6370 days) stand out as highly inflated planets orbiting slightly evolved F stars just after and in the turn-off points, respectively, which are among the least dense hot Jupiters, with densities of 0.153 g cm−3 and 0.180 g cm−3, respectively. All the presented exoplanets but HATS-27b are good targets for future atmospheric characterization studies, while HATS-27b is a prime target for Rossiter-McLaughlin monitoring in order to determine its spin-orbit alignment given the brightness (V=12.8) and stellar rotational velocity (vsini≈9.3 km/s) of the host star. These discoveries significantly increase the number of inflated hot Jupiters known, contributing to our understanding of the mechanism(s) responsible for hot Jupiter inflation.