The complex dynamical past and future of double eclipsing binary CzeV343: Misaligned orbits and period resonance
Abstract
CzeV343 (=V849 Aur) was previously identified as a candidate double eclipsing binary (2+2 quadruple), where the orbital periods of the two eclipsing binaries (P_{A} ≈ 1.2 days and P_{B} ≈ 0.8 days) lie very close to a 3:2 resonance. Here, we analyze 11 yr of groundbased photometry, four sectors of Transiting Exoplanet Survey Satellite (TESS) 2min and fullframe photometry, and two optical spectra. We construct a global model of our photometry, including apsidal motion of binary A and the lighttravel time effect (LTTE) of the mutual outer orbit, and explore the parameter space with Markov chain Monte Carlo. We estimate component masses for binary A (1.8 + 1.3 M_{⊙}) and binary B (1.4 + 1.2 M_{⊙}). We identify the pseudosynchronous rotation signal of binary A in TESS photometry. We detect apsidal motion in binary A with a period of about 33 yr, which is fully explained by tidal and rotational contributions of stars aligned with the orbit. The mutual orbit has a period of about 1450 days and an eccentricity of about 0.7. The LTTE amplitude is small, which points to low inclination of the outer orbit and a high degree of misalignment with the inner orbits. We find that when apsidal motion and the mutual orbit are taken into account, the orbital period resonance is exact to within 10^{−5} cycles/day. Many properties of CzeV343 are not compatible with requirements of the 3:2 resonance capture theory for coplanar orbits. Future evolution of CzeV343 can lead to mergers, triple common envelope, double white dwarf binaries, or a Type Ia supernova. More complex evolutionary pathways will likely arise from dynamical instability caused by orbital expansion when either of the binaries undergoes mass transfer. This instability has not been explored so far in 2+2 quadruples.
Full Table B.1 is only available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (ftp://130.79.128.5) or via https://cdsarc.cds.unistra.fr/vizbin/cat/J/A+A/667/A53
 Publication:

Astronomy and Astrophysics
 Pub Date:
 November 2022
 DOI:
 10.1051/00046361/202244335
 arXiv:
 arXiv:2206.12456
 Bibcode:
 2022A&A...667A..53P
 Keywords:

 binaries: close;
 binaries: eclipsing;
 stars: evolution;
 stars: individual: CzeV343;
 Astrophysics  Solar and Stellar Astrophysics
 EPrint:
 Accepted to A&