NGTS-7Ab: an ultrashort-period brown dwarf transiting a tidally locked and active M dwarf

Jackman, James A.G. and Wheatley, Peter J. and Bayliss, Dan and Gill, Samuel and Hodgkin, Simon T. and Burleigh, Matthew R. and Braker, Ian P. and Günther, Maximilian N. and Louden, Tom and Turner, Oliver and Anderson, David R. and Belardi, Claudia and Bouchy, Francois and Briegal, Joshua T. and Bryant, Edward M. and Cabrera Perez, Juan and Casewell, Sarah L. and Chaushev, Alexander and Costes, Jean C. and Csizmadia, Szilard and Eigmüller, Philipp and Erikson, Anders and Gänsicke, Boris T. and Gillen, Edward and Goad, Michael R. and Jenkins, James S. and McCormac, James and Moyano, Maximiliano and Nielsen, Louise D. and Pollacco, Don and Poppenhaeger, Katja and Queloz, Didier and Rauer, Heike and Raynard, Liam and Smith, Alexis and Udry, Stéphane and Vines, Jose I. and Watson, Christopher A. and West, Richard G. (2019) NGTS-7Ab: an ultrashort-period brown dwarf transiting a tidally locked and active M dwarf. Monthly Notices of the Royal Astronomical Society, 489 (4), pp. 5146-5164. Oxford University Press. doi: 10.1093/mnras/stz2496. ISSN 0035-8711.

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Abstract

We present the discovery of NGTS-7Ab, a high-mass brown dwarf transiting an M dwarf with a period of 16.2 h, discovered as part of the Next Generation Transit Survey (NGTS). This is the shortest period transiting brown dwarf around a main or pre-main sequence star to date. The M star host (NGTS-7A) has an age of roughly 55 Myr and is in a state of spin-orbit synchronization, which we attribute to tidal interaction with the brown dwarf acting to spin-up the star. The host star is magnetically active and shows multiple flares across the NGTS and follow-up light curves, which we use to probe the flare-star-spot phase relation. The host star also has an M star companion at a separation of 1.13 arcsec with very similar proper motion and systemic velocity, suggesting that the NGTS-7 system is a hierarchical triple. The combination of tidal synchronisation and magnetic braking is expected to drive on-going decay of the brown dwarf orbit, with a remaining lifetime of only 5-10 Myr.

Item URL in elib:

https://elib.dlr.de/131544/

Document Type:

Article

Title:

NGTS-7Ab: an ultrashort-period brown dwarf transiting a tidally locked and active M dwarf

Authors:

Authors	Institution or Email of Authors	Author's ORCID iD	ORCID Put Code
Jackman, James A.G.	Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK	UNSPECIFIED	UNSPECIFIED
Wheatley, Peter J.	Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK; Centre for Exoplanets and Habitability, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK	UNSPECIFIED	UNSPECIFIED
Bayliss, Dan	Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK; Centre for Exoplanets and Habitability, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK	UNSPECIFIED	UNSPECIFIED
Gill, Samuel	Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK; Centre for Exoplanets and Habitability, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK	UNSPECIFIED	UNSPECIFIED
Hodgkin, Simon T.	Institute of Astronomy, University of Cambridge, Madingley Rise, Cambridge CB3 0HA, UK	UNSPECIFIED	UNSPECIFIED
Burleigh, Matthew R.	Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK	UNSPECIFIED	UNSPECIFIED
Braker, Ian P.	Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK	UNSPECIFIED	UNSPECIFIED
Günther, Maximilian N.	Astrophysics Group, Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, UK; Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA	UNSPECIFIED	UNSPECIFIED
Louden, Tom	Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK; Centre for Exoplanets and Habitability, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK	UNSPECIFIED	UNSPECIFIED
Turner, Oliver	Geneva Observatory, University of Geneva, Chemin des Mailettes 51, CH-1290 Versoix, Switzerland	UNSPECIFIED	UNSPECIFIED
Anderson, David R.	Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK; Centre for Exoplanets and Habitability, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK	UNSPECIFIED	UNSPECIFIED
Belardi, Claudia	Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK	UNSPECIFIED	UNSPECIFIED
Bouchy, Francois	Geneva Observatory, University of Geneva, Chemin des Mailettes 51, CH-1290 Versoix, Switzerland	UNSPECIFIED	UNSPECIFIED
Briegal, Joshua T.	Astrophysics Group, Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, UK	UNSPECIFIED	UNSPECIFIED
Bryant, Edward M.	Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK; Centre for Exoplanets and Habitability, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK	UNSPECIFIED	UNSPECIFIED
Cabrera Perez, Juan	UNSPECIFIED	https://orcid.org/0000-0001-6653-5487	UNSPECIFIED
Casewell, Sarah L.	Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK	UNSPECIFIED	UNSPECIFIED
Chaushev, Alexander	Center for Astronomy and Astrophysics, TU Berlin, Hardenbergstr 36, D-10623 Berlin, Germany	UNSPECIFIED	UNSPECIFIED
Costes, Jean C.	Astrophysics Research Centre, Queen's University Belfast, 1 University Road, Belfast BT7 1NN, UK	UNSPECIFIED	UNSPECIFIED
Csizmadia, Szilard	UNSPECIFIED	UNSPECIFIED	UNSPECIFIED
Eigmüller, Philipp	UNSPECIFIED	https://orcid.org/0000-0003-4096-0594	UNSPECIFIED
Erikson, Anders	UNSPECIFIED	UNSPECIFIED	UNSPECIFIED
Gänsicke, Boris T.	Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK	UNSPECIFIED	UNSPECIFIED
Gillen, Edward	Astrophysics Group, Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, UK	UNSPECIFIED	UNSPECIFIED
Goad, Michael R.	Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK	UNSPECIFIED	UNSPECIFIED
Jenkins, James S.	Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile; Centro de Astrofísica y Tecnologías Afines (CATA), Casilla 36-D, Santiago, Chile	UNSPECIFIED	UNSPECIFIED
McCormac, James	Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK; Centre for Exoplanets and Habitability, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK	UNSPECIFIED	UNSPECIFIED
Moyano, Maximiliano	Instituto de Astronomía, Universidad Católica del Norte, Angamos 0610, 1270709 Antofagasta, Chile	UNSPECIFIED	UNSPECIFIED
Nielsen, Louise D.	Geneva Observatory, University of Geneva, Chemin des Mailettes 51, CH-1290 Versoix, Switzerland	UNSPECIFIED	UNSPECIFIED
Pollacco, Don	Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK; Centre for Exoplanets and Habitability, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK	UNSPECIFIED	UNSPECIFIED
Poppenhaeger, Katja	Astrophysics Research Centre, Queen's University Belfast, 1 University Road, Belfast BT7 1NN, UK; Leibniz Institute for Astrophysics Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam, Germany	UNSPECIFIED	UNSPECIFIED
Queloz, Didier	Astrophysics Group, Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, UK	UNSPECIFIED	UNSPECIFIED
Rauer, Heike	UNSPECIFIED	UNSPECIFIED	UNSPECIFIED
Raynard, Liam	Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK	UNSPECIFIED	UNSPECIFIED
Smith, Alexis	UNSPECIFIED	https://orcid.org/0000-0002-2386-4341	UNSPECIFIED
Udry, Stéphane	Geneva Observatory, University of Geneva, Chemin des Mailettes 51, CH-1290 Versoix, Switzerland	UNSPECIFIED	UNSPECIFIED
Vines, Jose I.	Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile	UNSPECIFIED	UNSPECIFIED
Watson, Christopher A.	Astrophysics Research Centre, Queen's University Belfast, 1 University Road, Belfast BT7 1NN, UK	UNSPECIFIED	UNSPECIFIED
West, Richard G.	Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK; Centre for Exoplanets and Habitability, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK	UNSPECIFIED	UNSPECIFIED

Date:

November 2019

Journal or Publication Title:

Monthly Notices of the Royal Astronomical Society

Refereed publication:

Yes

Open Access:

Yes

Gold Open Access:

In SCOPUS:

Yes

In ISI Web of Science:

Yes

Volume:

489

DOI:

10.1093/mnras/stz2496

Page Range:

pp. 5146-5164

Publisher:

Oxford University Press

ISSN:

0035-8711

Status:

Published

Keywords:

brown dwarfs, stars: flare, stars: individual: NGTS-7A, stars: low-mass, stars: rotation, Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Earth and Planetary Astrophysics

HGF - Research field:

Aeronautics, Space and Transport

HGF - Program:

Space

HGF - Program Themes:

Space Exploration

DLR - Research area:

Raumfahrt

DLR - Program:

R EW - Space Exploration

DLR - Research theme (Project):

R - Project PLATO (old)

Location:

Berlin-Adlershof

Institutes and Institutions:

Institute of Planetary Research > Extrasolar Planets and Atmospheres
Institute of Planetary Research > Leitungsbereich PF

Deposited By:

Eigmüller, Dr. Philipp

Deposited On:

02 Dec 2019 14:44

Last Modified:

28 Mar 2023 23:55

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