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NGTS clusters survey – III. A low-mass eclipsing binary in the Blanco 1 open cluster spanning the fully convective boundary

Smith, Gareth D. and Gillen, Edward and Queloz, Didier and Hillenbrand, Lynne A. and Acton, Jack S. and Alves, Douglas R. and Anderson, David R. and Bayliss, Daniel and Briegal, Joshua T. and Burleigh, Matthew R. and Casewell, Sarah L. and Delrez, Laetitia and Dransfield, Georgina and Ducrot, Elsa and Gill, Samuel and Gillon, Michaël and Goad, Michael R. and Günther, Maximilian N. and Henderson, Beth A. and Jenkins, James S. and Jehin, Emmanuel and Moyano, Maximiliano and Murray, Catriona A. and Pedersen, Peter P. and Sebastian, Daniel and Thompson, Samantha and Tilbrook, Rosanna H. and Triaud, Amaury H. M. J. and Vines, Jose I. and Wheatley, Peter J. (2021) NGTS clusters survey – III. A low-mass eclipsing binary in the Blanco 1 open cluster spanning the fully convective boundary. Monthly Notices of the Royal Astronomical Society, 507 (4). pp. 5991-6011. ISSN 0035-8711. doi:10.1093/mnras/stab2374.

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We present the discovery and characterization of an eclipsing binary identified by the Next Generation Transit Survey in the ∼115-Myr-old Blanco 1 open cluster. NGTS J0002−29 comprises three M dwarfs: a short-period binary and a companion in a wider orbit. This system is the first well-characterized, low-mass eclipsing binary in Blanco 1. With a low mass ratio, a tertiary companion, and binary components that straddle the fully convective boundary, it is an important benchmark system, and one of only two well-characterized, low-mass eclipsing binaries at this age. We simultaneously model light curves from NGTS, TESS, SPECULOOS, and SAAO, radial velocities from VLT/UVES and Keck/HIRES, and the system’s spectral energy distribution. We find that the binary components travel on circular orbits around their common centre of mass in P_(orb) = 1.098 005 24 ± 0.000 000 38 d, and have masses M_(pri) = 0.3978 ± 0.0033 M⊙ and M_(sec) = 0.2245 ± 0.0018 M_⊙, radii R_(pri) = 0.4037 ± 0.0048 R_⊙ and R_(sec) = 0.2759 ± 0.0055 R_⊙, and effective temperatures T_(pri) = 3372⁺⁴⁴₋₃₇ K and T_(sec) = 3231⁺³⁸₋₃₁ K. We compare these properties to the predictions of seven stellar evolution models, which typically imply an inflated primary. The system joins a list of 19 well-characterized, low-mass, sub-Gyr, stellar-mass eclipsing binaries, which constitute some of the strongest observational tests of stellar evolution theory at low masses and young ages.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Gillen, Edward0000-0003-2851-3070
Queloz, Didier0000-0002-3012-0316
Acton, Jack S.0000-0002-1860-7842
Alves, Douglas R.0000-0002-5619-2502
Anderson, David R.0000-0001-7416-7522
Bayliss, Daniel0000-0001-6023-1335
Briegal, Joshua T.0000-0002-7611-8772
Burleigh, Matthew R.0000-0003-0684-7803
Casewell, Sarah L.0000-0003-2478-0120
Delrez, Laetitia0000-0001-6108-4808
Dransfield, Georgina0000-0002-3937-630X
Ducrot, Elsa0000-0002-7008-6888
Gill, Samuel0000-0002-4259-0155
Gillon, Michaël0000-0003-1462-7739
Goad, Michael R.0000-0002-2908-7360
Günther, Maximilian N.0000-0002-3164-9086
Jenkins, James S.0000-0003-2733-8725
Jehin, Emmanuel0000-0001-8923-488X
Moyano, Maximiliano0000-0002-7927-9555
Murray, Catriona A.0000-0001-8504-5862
Triaud, Amaury H. M. J.0000-0002-5510-8751
Vines, Jose I.0000-0002-1896-2377
Wheatley, Peter J.0000-0003-1452-2240
Additional Information:© 2021 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model ( Accepted 2021 August 13. Received 2021 August 13; in original form 2020 July 16. Published: 07 September 2021. This research is based on data collected under the NGTS project at the ESO La Silla Paranal Observatory. The NGTS facility is funded by a consortium of institutes consisting of the University of Warwick, the University of Leicester, Queen’s University Belfast, the University of Geneva, the Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR; under the ‘Großinvestition GI-NGTS’), and the University of Cambridge, together with the UK Science and Technology Facilities Council (STFC; project reference ST/M001962/1). This work is also based on observations collected at the European Southern Observatory under ESO programme 0103.C-0902(A) and at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. This research received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement number 803193/BEBOP), and from the Science and Technology Facilities Council (STFC; grant numbers ST/S00193X/1 and ST/S00305/1). GDS gratefully acknowledges support by an STFC-funded PhD studentship and thanks Simon Hodgkin and Floor van Leeuwen for helpful discussion concerning the Gaia astrometry. EG gratefully acknowledges support from the David and Claudia Harding Foundation in the form of a Winton Exoplanet Fellowship. MNG acknowledges support from MIT’s Kavli Institute as a Juan Carlos Torres Fellow. LD is an F.R.S.-FNRS Postdoctoral Researcher. Finally, we would like to thank the referee, John Southworth, for his helpful and very positive report. Data Availability: The data underlying this article will be shared on reasonable request to the corresponding author.
Group:Astronomy Department
Funding AgencyGrant Number
University of WarwickUNSPECIFIED
University of LeicesterUNSPECIFIED
Queen’s University BelfastUNSPECIFIED
University of GenevaUNSPECIFIED
Deutsches Zentrum für Luft- und Raumfahrt (DLR)UNSPECIFIED
University of CambridgeUNSPECIFIED
Science and Technology Facilities Council (STFC)ST/M001962/1
European Research Council (ERC)803193
Science and Technology Facilities Council (STFC)ST/S00193X/1
Science and Technology Facilities Council (STFC)ST/S00305/1
David and Claudia Harding FoundationUNSPECIFIED
Winton Exoplanet FellowshipUNSPECIFIED
Massachusetts Institute of Technology (MIT)UNSPECIFIED
Fonds de la Recherche Scientifique (FNRS)UNSPECIFIED
Subject Keywords:binaries: eclipsing – binaries: spectroscopic – stars: evolution – stars: fundamental parameters – stars: low mass – open clusters and associations: individual: Blanco 1
Issue or Number:4
Record Number:CaltechAUTHORS:20211103-223054543
Persistent URL:
Official Citation:Gareth D Smith, Edward Gillen, Didier Queloz, Lynne A Hillenbrand, Jack S Acton, Douglas R Alves, David R Anderson, Daniel Bayliss, Joshua T Briegal, Matthew R Burleigh, Sarah L Casewell, Laetitia Delrez, Georgina Dransfield, Elsa Ducrot, Samuel Gill, Michaël Gillon, Michael R Goad, Maximilian N Günther, Beth A Henderson, James S Jenkins, Emmanuël Jehin, Maximiliano Moyano, Catriona A Murray, Peter P Pedersen, Daniel Sebastian, Samantha Thompson, Rosanna H Tilbrook, Amaury H M J Triaud, Jose I Vines, Peter J Wheatley, NGTS clusters survey – III. A low-mass eclipsing binary in the Blanco 1 open cluster spanning the fully convective boundary, Monthly Notices of the Royal Astronomical Society, Volume 507, Issue 4, November 2021, Pages 5991–6011,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:111738
Deposited By: Tony Diaz
Deposited On:04 Nov 2021 20:42
Last Modified:04 Nov 2021 20:42

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