Work

SOPHIE and TESS characterization of fourteen TESS objects of interest: Nine planetary systems and five low-mass stellar companions

Year: 2026

Type: article

Abstract: We present a study of fourteen objects of interest (TOIs) observed as part of the SOPHIE– follow-up program. Using photometry, SOPHIE radial velocities (RVs), ground-based photometry, and high-spatial resolution imaging, we characterized all targets and established their true nature. Among them, nine systems—TOI-6457, TOI-6883A, TOI-6649, TOI-6842A, TOI-5217A, TOI-6893A, TOI-7025, TOI-7176, and TOI-5893—are shown to host planets. We find that TOI-6649 b, TOI-6842A b, and TOI-5217A b are transiting hot Jupiters with orbital periods of approximately 4.4–6.0 d, radii of 1.3–1.6 R_̊m J, and masses of 0.3–1.3 M_̊m J, corresponding to bulk densities of 0.1–0.6 g cm TESS TESS TESS -3 $. Our RV data further reveal that TOI-5217A hosts an outer companion, TOI-5217A c, with a period of ∼1761 d, a minimum mass of ∼ 13 M_̊m J, and a significantly eccentric orbit (e = 0.53 ± 0.02). We also characterize TOI-5893 b, TOI-6893A b, TOI-6457 b, TOI-7176 b, and TOI-7025 b as transiting warm Jupiters, a relatively scarce population. Their orbital periods range from 40.4 to 67.0 days, with radii of 0.8–1.2 R_̊m J and masses of 0.5–1.0 M_̊m J. In addition, TOI-6883A b, a recently reported transiting warm Jupiter, is further characterized using new ground- and space-based photometry together with SOPHIE and TRES RVs. The remaining five systems—TOI-5621AB, TOI-5321AB, TOI-3678AB, TOI-5906AB, and TOI-5308AB—exhibit large RV semi-amplitudes indicative of eclipsing binaries. The companions have estimated masses of 0.1–0.6 M_⊙ and radii of 0.1–0.6 $ R_⊙$. Among our sample, TOI-6842A b stands out as an extremely low-density giant planet (ρ_ p = 0.08 ± 0.01, ), placing it in the super-puff category and making it rank among the nine lowest-density planets known to date. With a transmission spectroscopy metric of ∼250, it represents an excellent target for atmospheric characterization. Additionally, transiting planets TOI-6883A b, TOI-6893A b, TOI-6457 b, TOI-5893 b, TOI-7176 b, and TOI-7025 b, which each have equilibrium temperatures between 377 and 846 K, provide valuable low-irradiation benchmarks for control models of hot-Jupiter inflation. Furthermore, TOI-7025 b stands out due to its orbital eccentricity of 0.82$±0.02, one of the largest planetary eccentricities discovered so far for a planet orbiting a single star. Finally, using the astrometric excess noise, we detect TOI-5906 B, marking the first discovery of an object identified using all three techniques: transit, RV, and astrometry. -3 Gaia

Source: Astronomy and Astrophysics

DOI: 10.1051/0004-6361/202660112