@article{5dcd888121ee4f589e788ad101720e7f,
title = "The white dwarf binary pathways survey −III. Contamination from hierarchical triples containing a white dwarf",
abstract = "The White Dwarf Binary Pathways Survey aims at increasing the number of known detached A, F, G, and K main-sequence stars in close orbits with white dwarf companions (WD+AFGK binaries) to refine our understanding about compact binary evolution and the nature of Supernova Ia progenitors. These close WD+AFGK binary stars are expected to form through common envelope evolution, in which tidal forces tend to circularize the orbit. However, some of the identified WD+AFGK binary candidates show eccentric orbits, indicating that these systems are either formed through a different mechanism or perhaps they are not close WD+AFGK binaries. We observed one of these eccentric WD+AFGK binaries with SPHERE and find that the system TYC 7218-934-1 is in fact a triple system where the WD is a distant companion. The inner binary likely consists of the G-type star plus an unseen low-mass companion in an eccentric orbit. Based on this finding, we estimate the fraction of triple systems that could contaminate the WD+AFGK sample. We find that less than 15 per cent of our targets with orbital periods shorter than 100 d might be hierarchical triples.",
keywords = "Binaries: close, Dynamics, Methods: numerical, Methods: statistical, Stars: kinematics",
author = "F. Lagos and Schreiber, {M. R.} and Parsons, {S. G.} and A. Zurlo and D. Mesa and G{\"a}nsicke, {B. T.} and R. Brahm and C. Caceres and H. Canovas and Hernandez, {M. S.} and A. Jordan and D. Koester and L. Schmidtobreick and C. Tappert and M. Zorotovic",
note = "Funding Information: MRS acknowledges financial support from FONDECYT (grant number 1181404). SGP acknowledges the support of the STFC Ernest Rutherford Fellowship. AZ acknowledges support from the CONICYT/PAI (grant PAI77170087). BTG was supported by the UK STFC grant ST/P000495. RB acknowledges support from FONDECYT Post-doctoral Fellowship Project 3180246, and from the Millennium. Institute of Astrophysics (MAS). CC acknowledges support from DGI-UNAB project DI-11-19/R. MSH thanks Doctorado Nacional CONICYT 2017 folio 21170070. CT acknowledges financial support from Fondecyt No. 1170566. MZ acknowledges support from CONICYT/PAI (grant 79170121) and CONICYT/FONDECYT (grant 11170559). We also thank the referee Steve B. Howell for helpful suggestions that improved the presentation of this paper. Publisher Copyright: {\textcopyright} 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society",
year = "2020",
month = may,
day = "1",
doi = "10.1093/mnras/staa747",
language = "English",
volume = "494",
pages = "915--922",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "1",
}