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The First Science Results from Sphere: Disproving the Predicted Brown Dwarf Around V471 Tau

Hardy, A. and Schreiber, M. R. and Parsons, S. G. and Cáceres, C. and Retamales, G. and Wahhaj, Z. and Mawet, D. and Canovas, H. and Cieza, L. and Marsh, T. R. and Bours, M. C. P. and Dhillon, V. S. and Bayo, A. (2015) The First Science Results from Sphere: Disproving the Predicted Brown Dwarf Around V471 Tau. Astrophysical Journal Letters, 800 (2). Art. No. L24. ISSN 2041-8205. https://resolver.caltech.edu/CaltechAUTHORS:20150528-113208638

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Abstract

Variations of eclipse arrival times have recently been detected in several post-common envelope binaries consisting of a white dwarf and a main-sequence companion star. The generally favored explanation for these timing variations is the gravitational pull of one or more circumbinary substellar objects periodically moving the center of mass of the host binary. Using the new extreme-AO instrument SPHERE, we image the prototype eclipsing post-common envelope binary V471 Tau in search of the brown dwarf that is believed to be responsible for variations in its eclipse arrival times. We report that an unprecedented contrast of ${\Delta }{{m}_{H}}=12.1$ at a separation of 260 mas was achieved, but resulted in a non-detection. This implies that there is no brown dwarf present in the system unless it is 3 mag fainter than predicted by evolutionary track models, and provides damaging evidence against the circumbinary interpretation of eclipse timing variations. In the case of V471 Tau, a more consistent explanation is offered with the Applegate mechanism, in which these variations are prescribed to changes in the quadrupole moment within the main-sequence star.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1088/2041-8205/800/2/L24DOIArticle
http://iopscience.iop.org/2041-8205/800/2/L24/PublisherArticle
http://arxiv.org/abs/1502.05116arXivDiscussion Paper
ORCID:
AuthorORCID
Wahhaj, Z.0000-0001-8269-324X
Mawet, D.0000-0002-8895-4735
Canovas, H.0000-0001-7668-8022
Cieza, L.0000-0002-2828-1153
Marsh, T. R.0000-0002-2498-7589
Additional Information:© 2015 The American Astronomical Society. Received 2014 December 17; Accepted 2015 January 16; Published 2015 February 18. A.H., M.R.S., C.C., H.C., L.C., and A.B. acknowledge support from the Millennium Nucleus RC130007 (Chilean Ministry of Economy). M.R.S., S.P., C.C., L.C., and A.B. also acknowledge support from FONDECYT grants 1141269, 3140585, 3140592, 1440109, and 11140572, respectively. T.R.M. thanks the UK’s Science and Technology Facilities Council for support during the course of this work under grant ST/L000733/1.
Funders:
Funding AgencyGrant Number
Millennium NucleusRC130007
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)1141269
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)3140585
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)3140592
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)1440109
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)11140572
Science and Technology Facilities Council (STFC)ST/L000733/1
Subject Keywords:binaries: close; binaries: eclipsing; brown dwarfs; planet-star interactions; stars: individual (V471 Tau); white dwarfs
Issue or Number:2
Record Number:CaltechAUTHORS:20150528-113208638
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20150528-113208638
Official Citation:The First Science Results from Sphere: Disproving the Predicted Brown Dwarf Around V471 Tau. A. Hardy et al. 2015 ApJ 800 L24
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:57877
Collection:CaltechAUTHORS
Deposited By: Joanne McCole
Deposited On:28 May 2015 20:05
Last Modified:01 Nov 2019 04:49

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