HD207897 b: A dense sub-Neptune transiting a nearby and bright K-type star
Abstract
We present the discovery and characterization of a transiting sub-Neptune orbiting with a 16.20 day period around a nearby (28 pc) and bright(V=8.37) K0V star HD207897 (TOI-1611). This discovery is based on photometric measurements from the Transiting Exoplanet Survey Satellite(TESS) mission and radial velocity (RV) observations from the SOPHIE, Automated Planet Finder (APF) and HIRES high precision spectrographs. We used EXOFASTv2 for simultaneously modeling the parameters of the planet and its host star, combining photometric and RV data to determine the planetary system parameters. We show that the planet has a radius of 2.50+/-0.08 RE and a mass of either 14.4+/-1.6 ME or 15.9+/-1.6 ME with nearly equal probability; the two solutions correspond to two possibilities for the stellar activity period. Hence, the density is either 5.1+/-0.7 g cm^-3 or 5.5^{+0.8}_{-0.7} g cm^-3, making it one of the relatively rare dense sub-Neptunes. The existence of such a dense planet at only 0.12 AU from its host star is unusual in the currently observed sub-Neptune (2<RE<4) population. The most likely scenario is that this planet has migrated to its current position.
Cite
@article{arxiv.2110.08597,
title = {HD207897 b: A dense sub-Neptune transiting a nearby and bright K-type star},
author = {N. Heidari and I. Boisse and J. Orell-Mique and G. Hebrard and L. Acuna and N. C. Hara and J. Lillo-Box and J. D. Eastman and L. Arnold and N. Astudillo-Defru and V. Adibekyan and A. Bieryla and X. Bonfils and F. Bouchy and T. Barclay and C. E. Brasseur and S. Borgniet and V. Bourrier and L. Buchhave and A. Behmard and C. Beard and N. M . Batalha and B. Courcol and P. Cortes-Zuleta and K. Collins and A. Carmona and I. J. M. Crossfield and A. Chontos and X. Delfosse and S. Dalal and M. Deleuil and O. D. S. Demangeon and R. F. Diaz and X. Dumusque and T. Daylan and D. Dragomir and E. Delgado Mena and C. Dressing and F. Dai and P. A. Dalba and D. Ehrenreich and T. Forveille and B. Fulton and T. Fetherolf and G. Gaisne and S. Giacalone and N. Riazi and S. Hoyer and M. J. Hobson and A. W. Howard and D. Huber and M. L. Hill and L. A. Hirsch and H. Isaacson and J. Jenkins and S. R. Kane and F. Kiefer and R. Luque and D. W. Latham and J. Lubin and T. Lopez and O. Mousis and C. Moutou and G. Montagnier and L. Mignon and A. Mayo and T. Mocnik and J. M. A. Murphy and E. Palle and F. Pepe and E. A. Petigura and J. Rey and G. Ricker and P. Robertson and A. Roy and R. A. Rubenzahl and L. J. Rosenthal and A. Santerne and N. C. Santos and S. G. Sousa and K. G. Stassun and M. Stalport and N. Scarsdale and P. A. Strom and S. Seager and D. Segransan and P. Tenenbaum and R. Tronsgaard and S. Udry and R. Vanderspek and F. Vakili and J. Winn and L. M. Weiss},
journal= {arXiv preprint arXiv:2110.08597},
year = {2022}
}
Comments
18 pages, 12 figures, 6 tables; accepted for publication in the A&A journal; comments welcome