SOPHIE velocimetry of Kepler transit candidates. XV. KOI-614b, KOI-206b, and KOI-680b: a massive warm Jupiter orbiting a G0 metallic dwarf and two highly inflated planets with a distant companion around evolved F-type stars

TL;DR

This paper reports the discovery and detailed characterization of three new transiting exoplanets, including a massive warm Jupiter and two highly inflated planets, around evolved F-type stars, using SOPHIE radial velocity measurements.

Contribution

It presents the validation and detailed physical characterization of three new exoplanets, including their masses, radii, and orbital parameters, and discusses their implications for planetary formation and evolution models.

Findings

KOI-614b is a massive warm Jupiter with a 12.9-day orbit.

KOI-206b is an inflated hot Jupiter with a 5.3-day orbit, challenging planetary models.

KOI-680b is a large, low-mass planet orbiting a subgiant star, with signs of a distant companion.

Abstract

We report the validation and characterization of three new transiting exoplanets using SOPHIE radial velocities: KOI-614b, KOI-206b, and KOI-680b. KOI-614b has a mass of $2.86\pm0.35~{\rm M_{Jup}}$ and a radius of $1.13^{+0.26}_{-0.18}~{\rm R_{Jup}}$, and it orbits a G0, metallic ([Fe/H]=$0.35\pm0.15$) dwarf in 12.9 days. Its mass and radius are familiar and compatible with standard planetary evolution models, so it is one of the few known transiting planets in this mass range to have an orbital period over ten days. With an equilibrium temperature of $T_{eq}=1000 \pm 45$ K, this places KOI-614b at the transition between what is usually referred to as "hot" and "warm" Jupiters. KOI-206b has a mass of $2.82\pm 0.52~{\rm M_{Jup}}$ and a radius of $1.45\pm0.16~{\rm R_{Jup}}$, and it orbits a slightly evolved F7-type star in a 5.3-day orbit. It is a massive inflated hot Jupiter that is particularly challenging for planetary models because it requires unusually large amounts of additional dissipated energy in the planet. On the other hand, KOI-680b has a much lower mass of $0.84\pm0.15~{\rm M_{Jup}}$ and requires less extra-dissipation to explain its uncommonly large radius of $1.99\pm0.18~{\rm R_{Jup}}$. It is one of the biggest transiting planets characterized so far, and it orbits a subgiant F9-star well on its way to the red giant stage, with an orbital period of 8.6 days. With host stars of masses of $1.46\pm0.17~M_{\odot}$ and $1.54 \pm 0.09~M_{\odot}$, respectively, KOI-206b, and KOI-680b are interesting objects for theories of formation and survival of short-period planets around stars more massive than the Sun. For those two targets, we also find signs of a possible distant additional companion in the system.