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arXiv · 2402.09943

NGTS-28Ab: A short period transiting brown dwarf

Beth A. Henderson·Sarah L. Casewell·Michael R. Goad·Jack S. Acton·Maximilian N. Günther·Louise D. Nielsen·Matthew R. Burleigh·Claudia Belardi·Rosanna H. Tilbrook·Oliver Turner·Steve B. Howell·Catherine A. Clark·Colin Littlefield·Khalid Barkaoui·Douglas R. Alves·David R. Anderson·Daniel Bayliss·Francois Bouchy·Edward M. Bryant·George Dransfield·Elsa Ducrot·Philipp Eigmüller·Samuel Gill·Edward Gillen·Michaël Gillon·Faith Hawthorn·Matthew J. Hooton·James A. G. Jackman·Emmanuel Jehin·James S. Jenkins·Alicia Kendall·Monika Lendl·James McCormac·Maximiliano Moyano·Peter Pihlmann Pedersen·Francisco J. Pozuelos·Gavin Ramsay·Ramotholo R. Sefako·Mathilde Timmermans·Amaury H. M. J. Triaud·Stephane Udry·Jose I. Vines·Christopher A. Watson·Richard G. West·Peter J. Wheatley·Sebastián Zúñiga-Fernández
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Abstract

We report the discovery of a brown dwarf orbiting a M1 host star. We first identified the brown dwarf within the Next Generation Transit Survey data, with supporting observations found in TESS sectors 11 and 38. We confirmed the discovery with follow-up photometry from the South African Astronomical Observatory, SPECULOOS-S, and TRAPPIST-S, and radial velocity measurements from HARPS, which allowed us to characterise the system. We find an orbital period of ~1.25 d, a mass of 69.0+5.3-4.8 MJ, close to the Hydrogen burning limit, and a radius of 0.95 +- 0.05 RJ. We determine the age to be >0.5 Gyr, using model isochrones, which is found to be in agreement with SED fitting within errors. NGTS-28Ab is one of the shortest period systems found within the brown dwarf desert, as well as one of the highest mass brown dwarfs that transits an M dwarf. This makes NGTS-28Ab another important discovery within this scarcely populated region.

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Beth A. Henderson, Sarah L. Casewell, Michael R. Goad, Jack S. Acton, Maximilian N. Günther, Louise D. Nielsen, Matthew R. Burleigh, Claudia Belardi, Rosanna H. Tilbrook, Oliver Turner, Steve B. Howell, Catherine A. Clark, Colin Littlefield, Khalid Barkaoui, Douglas R. Alves, David R. Anderson, Daniel Bayliss, Francois Bouchy, Edward M. Bryant, George Dransfield, Elsa Ducrot, Philipp Eigmüller, Samuel Gill, Edward Gillen, Michaël Gillon, Faith Hawthorn, Matthew J. Hooton, James A. G. Jackman, Emmanuel Jehin, James S. Jenkins, Alicia Kendall, Monika Lendl, James McCormac, Maximiliano Moyano, Peter Pihlmann Pedersen, Francisco J. Pozuelos, Gavin Ramsay, Ramotholo R. Sefako, Mathilde Timmermans, Amaury H. M. J. Triaud, Stephane Udry, Jose I. Vines, Christopher A. Watson, Richard G. West, Peter J. Wheatley, Sebastián Zúñiga-Fernández. 2024-02-15. NGTS-28Ab: A short period transiting brown dwarf. https://arxiv.org/abs/2402.09943

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