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.

planets and satellites: fundamental parameters

techniques: photometric

techniques: radial velocities

stars: fundamental parameters

planets and satellites: individual: HD 219666 b

planets and satellites: detection

Author

M. Esposito

Thüringer Landessternwarte Tautenburg

D. J. Armstrong

The University of Warwick

D. Gandolfi

University of Turin

V Adibekyan

Universidade do Porto

Malcolm Fridlund

Leiden University

Chalmers, Space, Earth and Environment, Onsala Space Observatory

N. C. Santos

Universidade do Porto

J. H. Livingston

University of Tokyo

E. Delgado Mena

Universidade do 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

Princeton University

Massachusetts Institute of Technology (MIT)

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 Astrofisico de Canarias

University of La Laguna

P. G. Beck

University of La Laguna

Instituto Astrofisico de Canarias

S. C. C. Barros

Universidade do 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 Astrofisico de Canarias

O. Demangeon

Universidade do 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

Universidade do Porto

A. Fukui

National Astronomical Observatory of Japan

S. Grziwa

University of Cologne

E. W. Guenther

Thüringer Landessternwarte Tautenburg

D. Hidalgo

University of La Laguna

Instituto Astrofisico de Canarias

M. Hjorth

Aarhus University

T. Hirano

Tokyo Institute of Technology

S. Hojjatpanah

Universidade do Porto

E. Knudstrup

Aarhus University

J. Korth

University of Cologne

K. W. F. Lam

Technische Universität Berlin

J. de Leon

University of Tokyo

M. N. Lund

Aarhus University

R. Luque

University of La Laguna

Instituto Astrofisico de Canarias

S. Mathur

University of La Laguna

Instituto Astrofisico de Canarias

P. Montanes Rodriguez

Instituto Astrofisico de Canarias

University of La Laguna

N. Narita

National Institutes of Natural Sciences

University of Tokyo

Instituto Astrofisico de Canarias

Japan Science and Technology Agency

National Astronomical Observatory of Japan

D. Nespral

University of La Laguna

Instituto Astrofisico de Canarias

P. Niraula

Massachusetts Institute of Technology (MIT)

G. Nowak

Instituto Astrofisico de Canarias

University of La Laguna

H. P. Osborn

Aix Marseille University

E. Palle

Instituto Astrofisico de Canarias

University of La Laguna

M. Paetzold

University of Cologne

D. Pollacco

The University of Warwick

J. Prieto-Arranz

Instituto Astrofisico de Canarias

University of La Laguna

H. Rauer

Technische Universität Berlin

German Aerospace Center (DLR)

Freie Universität Berlin

S. Redfield

Wesleyan University

I Ribas

Institute of Space Studies of Catalonia (IEEC)

Consejo Superior de Investigaciones Científicas

S. G. Sousa

Universidade do 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 A165

Subject Categories

Astronomy, Astrophysics and Cosmology

Other Physics Topics

Condensed Matter Physics

Infrastructure

Onsala Space Observatory

DOI

10.1051/0004-6361/201834853

More information

Latest update

5/17/2019