HATS-47b, HATS-48Ab, HATS-49b, and HATS-72b: Four Warm Giant Planets Transiting K Dwarfs

Abstract

We report the discovery of four transiting giant planets around K dwarfs. The planets HATS-47b, HATS-48Ab, HATS-49b, and HATS-72b have masses of ${0.369}_{-0.021}^{+0.031}$ ${M}_{{\rm{J}}}$, ${0.243}_{-0.030}^{+0.022}$ ${M}_{{\rm{J}}}$, ${0.353}_{-0.027}^{+0.038}$ ${M}_{{\rm{J}}}$, and $0.1254\pm 0.0039$ ${M}_{{\rm{J}}}$, respectively, and radii of $1.117\pm 0.014$ ${R}_{{\rm{J}}}$, $0.800\pm 0.015$ ${R}_{{\rm{J}}}$, $0.765\pm 0.013$ ${R}_{{\rm{J}}}$, and $0.7224\pm 0.0032$ ${R}_{{\rm{J}}}$, respectively. The planets orbit close to their host stars with orbital periods of $3.9228$ days, $3.1317$ days, $4.1480$ days, and $7.3279$ days, respectively. The hosts are main-sequence K dwarfs with masses of ${0.674}_{-0.012}^{+0.016}$ ${M}_{\odot }$, $0.7279\,\pm 0.0066$ ${M}_{\odot }$, $0.7133\pm 0.0075$ ${M}_{\odot }$, and $0.7311\pm 0.0028$, and with V-band magnitudes of $V=14.829\pm 0.010$, $14.35\pm 0.11$, $14.998\pm 0.040$ and $12.469\pm 0.010$. The super-Neptune HATS-72b (a.k.a. WASP-191b and TOI 294.01) was independently identified as a transiting planet candidate by the HATSouth, WASP, and TESS surveys, and we present a combined analysis of all of the data gathered by each of these projects (and their follow-up programs). An exceptionally precise mass is measured for HATS-72b thanks to high-precision radial velocity (RV) measurements obtained with VLT/ESPRESSO, FEROS, HARPS, and Magellan/PFS. We also incorporate TESS observations of the warm Saturn–hosting systems HATS-47 (a.k.a. TOI 1073.01), HATS-48A, and HATS-49. HATS-47 was independently identified as a candidate by the TESS team, while the other two systems were not previously identified from the TESS data. The RV orbital variations are measured for these systems using Magellan/PFS. HATS-48A has a resolved $5\buildrel{\prime\prime}\over{.} 4$ neighbor in Gaia DR2, which is a common-proper-motion binary star companion to HATS-48A with a mass of 0.22 ${M}_{\odot }$ and a current projected physical separation of ∼1400 au.