TIC 168789840: A Sextuply-Eclipsing Sextuple Star System
Abstract
We report the discovery of a sextuply-eclipsing sextuple star system from TESS data, TIC 168789840, also known as TYC 7037-89-1, the first known sextuple system consisting of three eclipsing binaries. The target was observed in Sectors 4 and 5 during Cycle 1, with lightcurves extracted from TESS Full Frame Image data. It was also previously observed by the WASP survey and ASAS-SN. The system consists of three gravitationally-bound eclipsing binaries in a hierarchical structure of an inner quadruple system with an outer binary subsystem. Follow-up observations from several different observatories were conducted as a means of determining additional parameters. The system was resolved by speckle interferometry with a 0."42 separation between the inner quadruple and outer binary, inferring an estimated outer period of ~2 kyr. It was determined that the fainter of the two resolved components is an 8.217 day eclipsing binary, which orbits the inner quadruple that contains two eclipsing binaries with periods of 1.570 days and 1.306 days. MCMC analysis of the stellar parameters has shown that the three binaries of TIC 168789840 are "triplets", as each binary is quite similar to the others in terms of mass, radius, and Teff. As a consequence of its rare composition, structure, and orientation, this object can provide important new insight into the formation, dynamics, and evolution of multiple star systems. Future observations could reveal if the intermediate and outer orbital planes are all aligned with the planes of the three inner eclipsing binaries.
Cite
@article{arxiv.2101.03433,
title = {TIC 168789840: A Sextuply-Eclipsing Sextuple Star System},
author = {Brian P. Powell and Veselin B. Kostov and Saul A. Rappaport and Tamas Borkovits and Petr Zasche and Andrei Tokovinin and Ethan Kruse and David W. Latham and Benjamin T. Montet and Eric L. N. Jensen and Rahul Jayaraman and Karen A. Collins and Martin Masek and Coel Hellier and Phil Evans and Thiam-Guan Tan and Joshua E. Schlieder and Guillermo Torres and Alan P. Smale and Adam H. Friedman and Thomas Barclay and Robert Gagliano and Elisa V. Quintana and Thomas L. Jacobs and Emily A. Gilbert and Martti H. Kristiansen and Knicole D. Colon and Daryll M. LaCourse and Greg Olmschenk and Mark Omohundro and Jeremy D. Schnittman and Hans M. Schwengeler and Richard K. Barry and Ivan A. Terentev and Patricia Boyd and Allan R. Schmitt and Samuel N. Quinn and Andrew Vanderburg and Enric Palle and James Armstrong and George R. Ricker and Roland Vanderspek and S. Seager and Joshua N. Winn and Jon M. Jenkins and Douglas A. Caldwell and Bill Wohler and Bernie Shiao and Christopher J. Burke and Tansu Daylan and Joel Villasenor},
journal= {arXiv preprint arXiv:2101.03433},
year = {2021}
}