We confirm the planetary nature of a warm Jupiter transiting the early M dwarf TOI-1899, using a combination of available TESS photometry; high-precision, near-infrared spectroscopy with the Habitable-zone Planet Finder; and speckle and adaptive optics imaging. The data reveal a transiting companion on an ∼29-day orbit with a mass and radius of 0.66±0.07MJ and 1.15−0.05+0.04RJ, respectively. The star TOI-1899 is the lowest-mass star known to host a transiting warm Jupiter, and we discuss the follow-up opportunities afforded by a warm (Teq∼362 K) gas giant orbiting an M0 star. Our observations reveal that TOI-1899.01 is a puffy warm Jupiter, and we suggest additional transit observations to both refine the orbit and constrain the true dilution observed in TESS.
@article{arxiv.2007.07098,
title = {A warm Jupiter transiting an M dwarf: A TESS single transit event confirmed with the Habitable-zone Planet Finder},
author = {Caleb I. Cañas and Gudmundur Stefansson and Shubham Kanodia and Suvrath Mahadevan and William D. Cochran and Michael Endl and Paul Robertson and Chad F. Bender and Joe P. Ninan and Corey Beard and Jack Lubin and Arvind F. Gupta and Mark E. Everett and Andrew Monson and Robert F. Wilson and Hannah M. Lewis and Mary Brewer and Steven R. Majewski and Leslie Hebb and Rebekah I. Dawson and Scott A. Diddams and Eric B. Ford and Connor Fredrick and Samuel Halverson and Fred Hearty and Andrea S. J. Lin and Andrew J. Metcalf and Jayadev Rajagopal and Lawrence W. Ramsey and Arpita Roy and Christian Schwab and Ryan C. Terrien and Jason T. Wright},
journal= {arXiv preprint arXiv:2007.07098},
year = {2020}
}