HD 219666 b: a hot-Neptune from TESS Sector 1
Journal article, 2019
We report on the confirmation and mass determination of a transiting planet orbiting the old and inactive G7 dwarf star HD219666 (M-star = 0.92 +/- 0.03 M-circle dot, R-star = 1.03 +/- 0.03 R-circle dot, tau(star) = 10 +/- 2 Gyr). With a mass of M-b = 16.6 +/- 1.3 M-circle plus, a radius of R-b = 4.71 +/- 0.17 R-circle plus, and an orbital period of P-orb similar or equal to 6 days, HD219666 b is a new member of a rare class of exoplanets: the hot-Neptunes. The Transiting Exoplanet Survey Satellite (TESS) observed HD219666 (also known as TOI-118) in its Sector 1 and the light curve shows four transit-like events, equally spaced in time. We confirmed the planetary nature of the candidate by gathering precise radial-velocity measurements with the High Accuracy Radial velocity Planet Searcher (HARPS) at ESO 3.6 m. We used the co-added HARPS spectrum to derive the host star fundamental parameters (T-eff = 5527 +/- 65 K, log g(star) = 4.40 +/- 0.11 (cgs), [Fe/H] = 0.04 +/- 0.04 dex, log R-HK' = -5.07 +/- 0.03), as well as the abundances of many volatile and refractory elements. The host star brightness (V = 9.9) makes it suitable for further characterisation by means of in-transit spectroscopy. The determination of the planet orbital obliquity, along with the atmospheric metal-to-hydrogen content and thermal structure could provide us with important clues on the formation mechanisms of this class of objects.
techniques: photometric
planets and satellites: individual: HD 219666 b
stars: fundamental parameters
techniques: radial velocities
planets and satellites: fundamental parameters
planets and satellites: detection
Author
M. Esposito
Thüringer Landessternwarte Tautenburg
D. J. Armstrong
The University of Warwick
D. Gandolfi
University of Turin
V Adibekyan
University of Porto
Malcolm Fridlund
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Leiden University
N. C. Santos
University of Porto
J. H. Livingston
University of Tokyo
E. Delgado Mena
University of Porto
L. Fossati
Austrian Academy of Sciences
J. Lillo-Box
European Southern Observatory Santiago
O. Barragan
University of Turin
D. Barrado
Spanish Astrobiology Center (INTA-CSIC)
P. E. Cubillos
Austrian Academy of Sciences
B. Cooke
The University of Warwick
A. B. Justesen
Aarhus University
F. Meru
The University of Warwick
R. F. Diaz
Universidad de Buenos Aires
E. Dai
Massachusetts Institute of Technology (MIT)
Princeton University
L. D. Nielsen
University of Geneva
Carina Persson
Chalmers, Space, Earth and Environment, Onsala Space Observatory
P. J. Wheatley
The University of Warwick
A. P. Hatzes
Thüringer Landessternwarte Tautenburg
V. Van Eylen
Princeton University
M. M. Musso
University of Turin
R. Alonso
Instituto de Astrofísica de Canarias
University of La Laguna
P. G. Beck
Instituto de Astrofísica de Canarias
University of La Laguna
S. C. C. Barros
University of Porto
D. Bayliss
The University of Warwick
A. S. Bonomo
Istituto nazionale di astrofisica (INAF)
F. Bouchy
University of Geneva
D. J. A. Brown
The University of Warwick
E. Bryant
The University of Warwick
J. Cabrera
German Aerospace Center (DLR)
W. D. Cochran
The University of Texas at Austin
S. Csizmadia
German Aerospace Center (DLR)
H. Deeg
University of La Laguna
Instituto de Astrofísica de Canarias
O. Demangeon
University of Porto
M. Deleuil
Aix Marseille University
X. Dumusque
University of Geneva
P. Eigmuller
German Aerospace Center (DLR)
M. Endl
The University of Texas at Austin
A. Erikson
German Aerospace Center (DLR)
F. Faedi
The University of Warwick
P. Figueira
European Southern Observatory Santiago
University of Porto
A. Fukui
National Astronomical Observatory of Japan
S. Grziwa
University of Cologne
E. W. Guenther
Thüringer Landessternwarte Tautenburg
D. Hidalgo
Instituto de Astrofísica de Canarias
University of La Laguna
M. Hjorth
Aarhus University
T. Hirano
Tokyo Institute of Technology
S. Hojjatpanah
University of Porto
E. Knudstrup
Aarhus University
Judith Korth
University of Cologne
K. W. F. Lam
Technische Universität Berlin
J. de Leon
University of Tokyo
M. N. Lund
Aarhus University
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
Instituto de Astrofísica de Canarias
University of La Laguna
N. Narita
University of Tokyo
Japan Science and Technology Agency
National Institutes of Natural Sciences
Instituto de Astrofísica de Canarias
National Astronomical Observatory of Japan
D. Nespral
Instituto de Astrofísica de Canarias
University of La Laguna
P. Niraula
Massachusetts Institute of Technology (MIT)
G. Nowak
Instituto de Astrofísica de Canarias
University of La Laguna
H. P. Osborn
Aix Marseille University
E. Palle
Instituto de Astrofísica de Canarias
University of La Laguna
M. Paetzold
University of Cologne
D. Pollacco
The University of Warwick
J. Prieto-Arranz
Instituto de Astrofísica de Canarias
University of La Laguna
H. Rauer
German Aerospace Center (DLR)
Technische Universität Berlin
Freie Universität Berlin
S. Redfield
Wesleyan University
I Ribas
Spanish National Research Council (CSIC)
Institute of Space Studies of Catalonia (IEEC)
S. G. Sousa
University of Porto
A. M. S. Smith
German Aerospace Center (DLR)
M. Tala-Pinto
Heidelberg University
S. Udry
University of Geneva
J. N. Winn
Princeton University
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 623 623 A165Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Other Physics Topics
Condensed Matter Physics
Infrastructure
Onsala Space Observatory
DOI
10.1051/0004-6361/201834853