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.
planets and satellites: detection
planets and satellites: fundamental parameters
stars: fundamental parameters
planets and satellites: individual: HD15337 b & c
planetary systems
Author
D. Gandolfi
University of Turin
L. Fossati
IWF
J. H. Livingston
University of Tokyo
K.G. Stassun
Fisk University
Vanderbilt University
S. Grziwa
University of Cologne
O. Barragan
University of Oxford
Malcolm Fridlund
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Leiden University
D. Kubyshkina
IWF
Carina Persson
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
F. Dai
Massachusetts Institute of Technology (MIT)
Princeton University
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
The University of Texas at Austin
Sz. Csizmadia
German Aerospace Center (DLR)
M. D. Davies
NASA Ames Research Center
H. J. Deeg
Instituto de Astrofísica de Canarias
University of La Laguna
Ph. Eigmüller
German Aerospace Center (DLR)
M. Endl
The University of Texas at Austin
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
J. Korth
Czech Academy of Sciences
J. Li
NASA Ames Research Center
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
Instituto de Astrofísica de Canarias
National Institutes of Natural Sciences
University of Tokyo
Japan Science and Technology Agency
D. Nespral
University of La Laguna
Instituto de Astrofísica de Canarias
P. Niraula
Massachusetts Institute of Technology (MIT)
G. Nowak
Instituto de Astrofísica de Canarias
University of La Laguna
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
German Aerospace Center (DLR)
Technische Universität Berlin
Freie Universität Berlin
S. Redfield
Wesleyan University
I Ribas
Institute of Space Studies of Catalonia (IEEC)
Institute of Space Sciences (ICE) - CSIC
M. Skarka
Masaryk University
Czech Academy of Sciences
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
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
DOI
10.3847/2041-8213/ab17d9