HATS-71b: A Giant Planet Transiting an M3 Dwarf Star in TESS Sector 1

Abstract

We report the discovery of HATS-71b, a transiting gas giant planet on a = P 3.7955 day orbit around a = G 15.35 mag M3 dwarf star. HATS-71 is the coolest M dwarf star known to host a hot Jupiter. The loss of light during transits is 4.7%, more than in any other confirmed transiting planet system. The planet was identified as a candidate by the ground-based HATSouth transit survey. It was confirmed using ground-based photometry, spectroscopy, and imaging, as well as spacebased photometry from the NASA Transiting Exoplanet Survey Satellite mission (TIC 234523599). Combining all of these data, and utilizing GaiaDR2, we find that the planet has a radius of  1.024 0.018 R J and mass of  0.37 0.24 M J (95% confidence upper limit of <0.80 M J ), while the star has a mass of  0.4861 0.0060 M  and a radius of  0.4783 0.0060 R  .

TOI-1696 and TOI-2136: Constraining the Masses of Two Mini-Neptunes with the Habitable-Zone Planet Finder

“…In Figure 10 it is clear that larger exoplanets are unusual around cooler stars, and that larger radii exoplanets become even more sparse the cooler the star. Only 10 currently confirmed planets orbit stars with T eff <3500 K while also having a radius >2.8 R ⊕ (Konopacky et al 2010;Leggett et al 2014;Artigau et al 2015;Bakos et al 2020;Castro González et al 2020;Fontanive et al 2020;Stefánsson et al 2020c;Parviainen et al 2021;Wells et al 2021;Zhang et al 2021). Further, only five of these are close to their star, with P orb <100 days.…”

TOI-1696 and TOI-2136: Constraining the Masses of Two Mini-Neptunes with HPF

“…In Figure 10 it is clear that larger exoplanets are unusual around cooler stars, and that larger radii exoplanets become even more sparse the cooler the star. Only 10 currently confirmed planets orbit stars with T eff < 3500 K while also having a radius > 2.8 R ⊕ (Konopacky et al 2010;Leggett et al 2014;Artigau et al 2015;Fontanive et al 2020;Bakos et al 2020;Stefánsson et al 2020c;Castro González et al 2020;Wells et al 2021;Parviainen et al 2021;Zhang et al 2021). Further, only 5 of these are close to their star, with P orb < 100 days.…”

A Warm Jupiter Transiting an M Dwarf: A TESS Single-transit Event Confirmed with the Habitable-zone Planet Finder

“…While ground-based surveys have been important in the detection and characterization of hot Jupiters with periods <10 days, transiting WJs are challenging to discover from the ground. As of this writing, there are four known short-period (<10 days) transiting Jupiter-sized exoplanets orbiting M dwarfs: Kepler-45 b (Johnson et al 2012), HATS-6 b (Hartman et al 2015), NGTS-1 b (Bayliss et al 2018), and HATS-71 b (Bakos et al 2020). Some WJs orbiting M dwarfs have been detected through the RV method (e.g., Delfosse et al 1998;Marcy et al 1998;Morales et al 2019), but none have been shown to transit.…”