John M. Jenkins | Searcharxiv

arXiv2025

TOI-7166 b: A Habitable Zone mini-Neptune planet around a nearby low-mass star

We present the discovery and validation of TOI-7166b, a 2.01+/-0.05R_Earth planet orbiting a nearby low-mass star. We validated the planet by combining TESS and multi-color high-precision photometric observations from ground-based telescopes, together with spectroscopic data, high-contrast imaging, archival images, and statistical arguments. The host star is an M4-type dwarf at a distance of ~35 pc from the Sun. It has a mass and a radius of Ms=0.190+/-0.004M_Sun and Rs=0.222+/-0.005R_Sun, respectively. TOI-7166b has an orbital period of 12.9 days, which places it close to the inner edge of the Habitable Zone of its host star, receiving an insolation flux of Sp=1.07+/-0.08S_Earth and an equilibrium temperature of Teq=249+/-5K (assuming a null Bond albedo). The brightness of the host star makes TOI-7166 a suitable target for radial velocity follow-up to measure the planetary mass and bulk density. Moreover, the physical parameters of the system including the infrared brightness (Kmag = 10.6) of the star and the planet-to-star radius ratio (0.0823+/-0.0012) make TOI-7166b an exquisite target for transmission spectroscopic observations with the JWST, to constrain the exoplanet atmospheric compositions.

astro-ph.EP↗

arXiv2021

Systematic Phase Curve Study of Known Transiting Systems from Year 1 of the TESS Mission

We present a systematic phase curve analysis of known transiting systems observed by the Transiting Exoplanet Survey Satellite (TESS) during year one of the primary mission. Using theoretical predictions for the amplitude of the planetary longitudinal atmospheric brightness modulation, stellar ellipsoidal distortion and Doppler boosting, as well as brightness considerations to select targets with likely detectable signals, we applied a uniform data processing and light-curve modeling framework to fit the full-orbit phase curves of 22 transiting systems with planet-mass or brown dwarf companions, including previously published systems. Statistically significant secondary eclipse depths and/or atmospheric brightness modulation amplitudes were measured for HIP 65A, WASP-18, WASP-19, WASP-72, WASP-100, WASP-111, WASP-121, and WASP-122/KELT-14. For WASP-100b, we found marginal evidence that the brightest region of the atmosphere is shifted eastward away from the substellar point. We detected significant ellipsoidal distortion signals in the light curves of HIP 65A, TOI-503, WASP-18, and WASP-30, with HIP 65A, TOI-503 and WASP-18 also exhibiting Doppler boosting. The measured amplitudes of these signals agree with the predictions of theoretical models. Combining the optical secondary eclipse depths with previously published Spitzer 3.6 and 4.5 $μ$m measurements, we derived dayside brightness temperatures and visible-light geometric albedos for a subset of the analyzed systems. We also calculated updated transit ephemerides combining the transit timings from the TESS light curves with previous literature values.

astro-ph.EP↗