TOI-421 c Archives

The ATREIDES Program In Search Of Lost Exo-Neptunes

by Keith CowingSeptember 17, 2025September 17, 2025

An international team led by the University of Geneva (UNIGE), including scientists from the National Centre of Competence in Research PlanetS, the University of Warwick, and the Canary Islands Institute […]

Stability analysis of the TOI-421 planetary system. For fixed initial conditions (Table 6), the parameter space of the system was explored by varying the orbital period Pb and the eccentricity eb of planet-b (left panel) and the eccentricities of both planets (right panel). The step size was 10−3 day in orbital period and 0.0025 in eccentricity. For each initial condition, the system was integrated over 5000 yr and a stability indicator was calculated, which involved a frequency analysis of the mean longitude of the inner planet. The chaotic diffusion was measured by the variation in the frequency (see text). Red points correspond to highly unstable orbits, while blue points correspond to orbits which are likely to be stable on a billion-years timescale. The black dots show the values of the best fit solution (Table 6). -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Characterisation Of The TOI-421 Planetary System Using CHEOPS, TESS, and Archival Radial Velocity Data

by Keith CowingApril 20, 2024

The TOI-421 planetary system contains two sub-Neptune-type planets and is a prime target to study the formation and evolution of planets and their atmospheres.