Triply eclipsing triple stars in the northern TESS fields: TICs 193993801, 388459317, and 52041148

Abstract

In this work we report the discovery and analysis of three new triply eclipsing triple star systems found with the TESS mission during its observations of the northern skies: TICs 193993801, 388459317, and 52041148. We utilized the TESS precision photometry of the binary eclipses and third-body eclipsing events, ground-based archival and follow-up photometric data, eclipse timing variations, archival spectral energy distributions, as well as theoretical evolution tracks in a joint photodynamical analysis to deduce the system masses and orbital parameters of both the inner and outer orbits. In one case (TIC 193993801) we also obtained radial velocity measurements of all three stars. This enabled us to ‘calibrate’ our analysis approach with and without ‘truth’ (i.e., RV) data. We find that the masses are good to 1-3% accuracy with RV data and 3-10% without the use of RV data. In all three systems we were able to find the outer orbital period before doing any detailed analysis by searching for a longer-term periodicity in the ASAS-SN archival photometry data—just a few thousand ASAS-SN points enabled us to find the outer periods of 49.28 d, 89.86 d, and 177.0 d, respectively. From our full photodynamical analysis we find that all three systems are coplanar to within 1○ − 3○. The outer eccentricities of the three systems are 0.003, 0.10, and 0.62, respectively (i.e., spanning a factor of 200). The masses of the three stars {Aa, Ab, and B} in the three systems are: {1.31, 1.19, 1.34}, {1.82, 1.73, 2.19}, and {1.62, 1.48, 2.74} M⊙, respectively.

Eclipsing Binaries in Dynamically Interacting Close, Multiple Systems

“…In addition to the dynamical determination of the relative orbital inclinations, the discovery of triply eclipsing systems offers another opportunity since the shape and timing of the extra eclipses are extremely sensitive to the relative configuration and movement of the three stars (or, two stars and a circumbinary planet). Via careful modeling of the extra eclipses, the mutual inclination can be accurately determined even in the absence of detectable third-body perturbations (Borkovits et al [23]; Masuda et al [165]; Mitnyan et al [154]; Borkovits et al [155]).…”

“…However, these higher order, non-vanishing DE contributions in the flat, doubly circular case will remain small, and turn out to be negligible in practice. This scenario is realized in at least three known triply eclipsing ECHTs (HD 181068, Borkovits et al [23]; TIC 278825952, Mitnyan et al [154]; TIC 193993801, Borkovits et al [155]), where numerical integrations have justified that, despite the tightness of these systems, their observed ETVs are dominated exclusively by LTTE.…”

“…Apart from TIC 278825952, which is located in the SCVZ of TESS and, hence, was almost continuously observed during Cycles 1 and 3 (Mitnyan et al [154]), the other four were seen by TESS only during a few 25-27 daylong sectors. Therefore, inclusion of data sets of former, archival, or ongoing surveys such as SuperWASP (Pollaco et al [174]), ASAS-SN (Kochanek et al [175]), ATLAS (Heinze et al [176]), and KELT (Pepper et al [177]), as well as additional ground-based follow-up observations were crucial to their investigations (Borkovits et al [24,155]). Note, also, that we are aware of the discovery of some dozens of additional triply eclipsing triples in the TESS data.…”

Eclipsing Binaries in Dynamically Interacting Close, Multiple Systems

“…However, these higher order, non-vanishing DE contributions in the flat, doubly circular case will remain small, and turn out to be negligible in practice. This scenario is realized in at least three known triply eclipsing ECHTs (HD 181068, Borkovits et al [23]; TIC 278825952, Mitnyan et al [155]; and TIC 193993801, Borkovits et al [156]), where numerical integrations have justified that, despite the tightness of these systems, their observed ETVs are dominated exclusively by LTTE.…”

New low mass ratio contact binaries in the Catalina Sky Survey

“…However, Gaia is insensitive to short-period triples and systems where photocentre does not move significantly (see Fig.4 Belokurov et al 2020). This is the case of systems detected by TESS with RUWE ≤ 1.4 like TIC 388459317 (0.952), TIC 52041148 (1.052) (Borkovits et al 2022) or even quadruples like TIC 278956474 (1.06) (Rowden et al 2020) where the low RUWE value suggests the two binaries are likely to be tightly bound.…”