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.
@article{arxiv.2402.09943,
title = {NGTS-28Ab: A short period transiting brown dwarf},
author = {Beth A. Henderson and Sarah L. Casewell and Michael R. Goad and Jack S. Acton and Maximilian N. Günther and Louise D. Nielsen and Matthew R. Burleigh and Claudia Belardi and Rosanna H. Tilbrook and Oliver Turner and Steve B. Howell and Catherine A. Clark and Colin Littlefield and Khalid Barkaoui and Douglas R. Alves and David R. Anderson and Daniel Bayliss and Francois Bouchy and Edward M. Bryant and George Dransfield and Elsa Ducrot and Philipp Eigmüller and Samuel Gill and Edward Gillen and Michaël Gillon and Faith Hawthorn and Matthew J. Hooton and James A. G. Jackman and Emmanuel Jehin and James S. Jenkins and Alicia Kendall and Monika Lendl and James McCormac and Maximiliano Moyano and Peter Pihlmann Pedersen and Francisco J. Pozuelos and Gavin Ramsay and Ramotholo R. Sefako and Mathilde Timmermans and Amaury H. M. J. Triaud and Stephane Udry and Jose I. Vines and Christopher A. Watson and Richard G. West and Peter J. Wheatley and Sebastián Zúñiga-Fernández},
journal= {arXiv preprint arXiv:2402.09943},
year = {2024}
}
Comments
20 pages (inc. appendices), 16 figures, accepted for publication in MNRAS