2016AJ....152..108E

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 of ∼12-14 and have masses in the largely populated 0.5{M}_{J}–0.7{M}{J} region of parameter space but span a wide variety of radii, from 1.17{R}_{J} to 1.75{R}_{J}. HATS-25b, HATS-28b, HATS-29b, and HATS-30b are typical inflated hot Jupiters ({R}_{{p}=1.17–1.26{R}}{J}) orbiting G-type stars in short period (P=3.2-4.6 days) orbits. However, HATS-26b ({R}_{p}=1.75{R}{J}, P=3.3024 days) and HATS-27b ({R}_{p}=1.50{R}{J}, 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.