The Transiting Multi-planet System HD15337: Two Nearly Equal-mass Planets Straddling the Radius Gap
Journal article, 2019
We report the discovery of a super-Earth and a sub-Neptune transiting the star HD 15337 (TOI-402, TIC 120896927), a bright (V = 9) K1 dwarf observed by the Transiting Exoplanet Survey Satellite (TESS) in Sectors 3 and 4. We combine the TESS photometry with archival High Accuracy Radial velocity Planet Searcher spectra to confirm the planetary nature of the transit signals and derive the masses of the two transiting planets. With an orbital period of 4.8 days, a mass of {7.51}-1.01+1.09 {M}\oplus and a radius of 1.64 ± 0.06 R ⊕, HD 15337 b joins the growing group of short-period super-Earths known to have a rocky terrestrial composition. The sub-Neptune HD 15337 c has an orbital period of 17.2 days, a mass of {8.11}-1.69+1.82 {{{M}}}\oplus , and a radius of 2.39 ± 0.12 R ⊕, suggesting that the planet might be surrounded by a thick atmospheric envelope. The two planets have similar masses and lie on opposite sides of the radius gap, and are thus an excellent testbed for planet formation and evolution theories. Assuming that HD 15337 c hosts a hydrogen-dominated envelope, we employ a recently developed planet atmospheric evolution algorithm in a Bayesian framework to estimate the history of the high-energy (extreme ultraviolet and X-ray) emission of the host star. We find that at an age of 150 Myr, the star possessed on average between 3.7 and 127 times the high-energy luminosity of the current Sun.
planetary systems
planets and satellites: fundamental parameters
stars: fundamental parameters
planets and satellites: detection
planets and satellites: individual: HD15337 b & c
Author
D. Gandolfi
University of Turin
L. Fossati
IWF
J. H. Livingston
University of Tokyo
K.G. Stassun
Vanderbilt University
Fisk University
S. Grziwa
University of Cologne
O. Barragan
University of Oxford
Malcolm Fridlund
Leiden University
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
D. Kubyshkina
IWF
Carina Persson
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
F. Dai
Princeton University
Massachusetts Institute of Technology (MIT)
K. W. F. Lam
Technische Universität Berlin
S. Albrecht
Aarhus University
N. Batalha
University of California
P. G. Beck
University of La Laguna
Instituto de Astrofísica de Canarias
A. B. Justesen
Aarhus University
J. Cabrera
German Aerospace Center (DLR)
S. P. Cartwright
University of La Laguna
W. D. Cochran
University of Texas
Sz. Csizmadia
German Aerospace Center (DLR)
M. D. Davies
National Aeronautics and Space Administration (NASA)
H. J. Deeg
Instituto de Astrofísica de Canarias
University of La Laguna
Ph. Eigmüller
German Aerospace Center (DLR)
M. Endl
University of Texas
A. Erikson
German Aerospace Center (DLR)
M. Esposito
Thüringer Landessternwarte Tautenburg
R. A. García
Paris Diderot University
R. Goeke
Massachusetts Institute of Technology (MIT)
L. González-Cuesta
University of La Laguna
Instituto de Astrofísica de Canarias
E. W. Guenther
Thüringer Landessternwarte Tautenburg
A. P. Hatzes
Thüringer Landessternwarte Tautenburg
D. Hidalgo
Instituto de Astrofísica de Canarias
T. Hirano
Tokyo Institute of Technology
M. Hjorth
Aarhus University
P. Kabath
Czech Academy of Sciences
E. Knudstrup
Aarhus University
Judith Korth
Czech Academy of Sciences
J. Li
National Aeronautics and Space Administration (NASA)
R. Luque
Instituto de Astrofísica de Canarias
University of La Laguna
S. Mathur
Instituto de Astrofísica de Canarias
University of La Laguna
P. Montanes Rodriguez
University of La Laguna
Instituto de Astrofísica de Canarias
N. Narita
Japan Science and Technology Agency
University of Tokyo
National Institutes of Natural Sciences
Instituto de Astrofísica de Canarias
D. Nespral
University of La Laguna
Instituto de Astrofísica de Canarias
P. Niraula
Massachusetts Institute of Technology (MIT)
G. Nowak
University of La Laguna
Instituto de Astrofísica de Canarias
E. Palle
University of La Laguna
Instituto de Astrofísica de Canarias
M. Pätzold
Fisk University
J. Prieto-Arranz
University of La Laguna
Instituto de Astrofísica de Canarias
H. Rauer
Technische Universität Berlin
Freie Universität Berlin
German Aerospace Center (DLR)
S. Redfield
Wesleyan University
I Ribas
Spanish National Research Council (CSIC)
Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)
M. Skarka
Czech Academy of Sciences
Masaryk University
A. M S Smith
German Aerospace Center (DLR)
P. Rowden
Open University
G. Torres
Harvard-Smithsonian Center for Astrophysics
Vincent Van Eylen
Princeton University
Michael L. Vezie
Massachusetts Institute of Technology (MIT)
Astrophysical Journal Letters
2041-8205 (ISSN) 2041-8213 (eISSN)
Vol. 876 2 L24Exoplanets from space – CHEOPS and PLATO, ESA’s next two projects
Swedish National Space Board (174/18), 2017-01-01 -- 2022-12-31.
Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
DOI
10.3847/2041-8213/ab17d9