We report the detection of a transiting super-Earth-sized planet (R=1.39+-0.09 Rearth) in a 1.4-day orbit around L 168-9 (TOI-134),a bright M1V dwarf (V=11, K=7.1) located at 25.15+-0.02 pc. The host star was observed in the first sector of the Transiting Exoplanet Survey Satellite (TESS) mission and, for confirmation and planet mass measurement, was followed up with ground-based photometry, seeing-limited and high-resolution imaging, and precise radial velocity (PRV) observations using the HARPS and PFS spectrographs. Combining the TESS data and PRV observations, we find the mass of L168-9 b to be 4.60+-0.56 Mearth, and thus the bulk density to be 1.74+0.44-0.33 times larger than that of the Earth. The orbital eccentricity is smaller than 0.21 (95% confidence). This planet is a Level One Candidate for the TESS Mission's scientific objective - to measure the masses of 50 small planets - and is one of the most observationally accessible terrestrial planets for future atmospheric characterization.
@article{arxiv.2001.09175,
title = {A hot terrestrial planet orbiting the bright M dwarf L 168-9 unveiled by TESS},
author = {N. Astudillo-Defru and R. Cloutier and S. X. Wang and J. Teske and R. Brahm and C. Hellier and G. Ricker and R. Vanderspek and D. Latham and S. Seager and J. N. Winn and J. M. Jenkins and K. A. Collins and K. G. Stassun and C. Ziegler and J. M. Almenara and D. R. Anderson and E. Artigau and X. Bonfils and F. Bouchy and C. Briceño and R. P. Butler and D. Charbonneau and D. M. Conti and J. Crane and I. J . M. Crossfield and M. Davies and X. Delfosse and R. F. Díaz and R. Doyon and D. Dragomir and J. D. Eastman and N. Espinoza and Z. Essack and F. Feng and P. Figueira and T. Forveille and T. Gan and A. Glidden and N. Guerrero and R. Hart and Th. Henning and E. P. Horch and G. Isopi and J. S. Jenkins and A. Jordán and J. F. Kielkopf and N. Law and C. Lovis and F. Mallia and A. W. Mann and J. R. de Medeiros and C. Melo and R. E. Mennickent and L. Mignon and F. Murgas and D. A. Nusdeo and F. Pepe and H. M. Relles and M. Rose and N. C. Santos and D. Ségransan and S. Shectman and A. Shporer and J. C. Smith and P. Torres and S. Udry and J. Villasenor and J . G. Winters and G. Zhou},
journal= {arXiv preprint arXiv:2001.09175},
year = {2020}
}
Comments
14 pages, 8 figures, 3 tables. Accepted for publication in astronomy and Astrophysics