A hierarchical quadruple system revealed by eclipse timing variations and radial velocities: TIC 263930790

ABSTRACT We present the first comprehensive study of the eclipsing binary TIC 263930790, in which space-based photometry, spectroscopy, and eclipse-timing variations (ETVs) jointly reveal its hierarchical multiple-star architecture. We determine the effective temperature of the primary via spectral energy distribution modelling, and perform a simultaneous light and radial velocity (RV) curve analysis to derive the absolute parameters of the inner binary. Comparison with stellar evolutionary models places both components on the main sequence and indicates a system age of approximately 1.3 Gyr, with the primary component approaching the terminal-age main sequence while the system remains well detached. Broadening function (BF) analysis reveals spectral signatures of an additional luminous component, allowing for the measurement of its RVs. The ETVs are well reproduced by a model consisting of two light-time effect (LiTE) signals plus a quadratic ephemeris term, indicating the presence of two stellar-mass companions on eccentric outer orbits and favouring a hierarchical 2 + 1 + 1 quadruple architecture. By comparing the ETV-derived solutions with the observed RV signal of the additional body, we find that the outermost companion provides an excellent match, whereas attributing the RV modulation to the inner companion is strongly disfavoured. N-body integrations further demonstrate that the inferred configuration is dynamically stable over 200 Myr, with bounded secular variations of the orbital elements. TIC 263930790 thus represents a rare example of a dynamically stable, young hierarchical quadruple system whose architecture and evolutionary state can be robustly constrained in the absence of outer eclipses.