Discovery of the most compact 3+1-type quadruple star system TIC 120362137

Article l Open access l Published: 03 March 2026 l Nature Communications

Abstract

Hierarchical multiple stellar systems with short outer periods comprise an important subgroup of multiple star systems. In this paper we present the discovery and spectro-photodynamical analysis of the most compact known 3+1 quadruple stellar system, TIC 120362137. Through investigations of the observations made with the TESS satellite and ground-based follow up measurements, we find that the system consists of an eclipsing binary with a few-day-period that in turn eclipses, and is eclipsed by, a third star on a Pmid = 51.3 d orbit. This inner subsystem, which contains three stars that are more massive and hotter than the Sun, is more spatially compact than Mercury’s orbit around our Sun, and is orbited by a fourth Sun-like star with a period Pout = 1046 d. We detect the spectral lines of all four stars, making this system the most thoroughly studied 3+1 type quadruple stellar system. The future evolution of TIC 120362137 is also modeled, and we conclude that this entire system will likely end up as a pair of white dwarfs.

Cite this article

Borkovits, T., Rappaport, S.A., Chen, HL. et al. Discovery of the most compact 3+1-type quadruple star system TIC 120362137. Nat Commun 17, 1859 (2026). https://doi.org/10.1038/s41467-026-69223-4