HD 20329b: An ultra-short-period planet around a solar-type star found by TESS
Journal article, 2022

Context. Ultra-short-period (USP) planets are defined as planets with orbital periods shorter than one day. This type of planets is rare, highly irradiated, and interesting because their formation history is unknown. Aims. We aim to obtain precise mass and radius measurements to confirm the planetary nature of a USP candidate found by the Transiting Exoplanet Survey Satellite (TESS). These parameters can provide insights into the bulk composition of the planet candidate and help to place constraints on its formation history. Methods. We used TESS light curves and HARPS-N spectrograph radial velocity measurements to establish the physical properties of the transiting exoplanet candidate found around the star HD 20329 (TOI-4524). We performed a joint fit of the light curves and radial velocity time series to measure the mass, radius, and orbital parameters of the candidate. Results. We confirm and characterize HD 20329b, a USP planet transiting a solar-type star. The host star (HD 20329, V = 8.74 mag, J = 7.5 mag) is characterized by its G5 spectral type with M∗ = 0.90 ± 0.05 M⊙, R∗ = 1.13 ± 0.02 R⊙, and Teff = 5596 ± 50 K; it is located at a distance d = 63.68 ± 0.29 pc. By jointly fitting the available TESS transit light curves and follow-up radial velocity measurements, we find an orbital period of 0.9261 ± (0.5 ×10-4) days, a planetary radius of 1.72 ± 0.07 R∗, and a mass of 7.42 ± 1.09 M∗, implying a mean density of ρp = 8.06 ± 1.53 g cm-3. HD 20329b joins the ~30 currently known USP planets with radius and Doppler mass measurements.

Techniques: photometric

Techniques: radial velocities

Planets and satellites: detection

Author

F. Murgas

Instituto de Astrofísica de Canarias

University of La Laguna

G. Nowak

University of La Laguna

Instituto de Astrofísica de Canarias

T. Masseron

Instituto de Astrofísica de Canarias

University of La Laguna

H. Parviainen

Instituto de Astrofísica de Canarias

University of La Laguna

R. Luque

Institute of Astrophysics of Andalusia (IAA)

University of Chicago

Enric Palle

University of La Laguna

Instituto de Astrofísica de Canarias

Judith Korth

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

Ilaria Carleo

University of La Laguna

Instituto de Astrofísica de Canarias

Szilard Csizmadia

German Aerospace Center (DLR)

E. Esparza-Borges

University of La Laguna

Instituto de Astrofísica de Canarias

A. Alqasim

University College London (UCL)

William D. Cochran

The University of Texas at Austin

Fei Dai

California Institute of Technology (Caltech)

H. Deeg

Instituto de Astrofísica de Canarias

University of La Laguna

D. Gandolfi

University of Turin

E. Goffo

University of Turin

Thüringer Landessternwarte Tautenburg

Petr Kabath

Czech Academy of Sciences

K. W.F. Lam

German Aerospace Center (DLR)

J.H. Livingston

The Graduate University for Advanced Studies (SOKENDAI)

National Astronomical Observatory of Japan

National Institutes of Natural Sciences

Alexandra Muresan

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

H. L.M. Osborne

University College London (UCL)

Carina Persson

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

L. M. Serrano

University of Turin

Alexis M. S. Smith

German Aerospace Center (DLR)

Vincent Van Eylen

University College London (UCL)

J. Orell-Miquel

Instituto de Astrofísica de Canarias

University of La Laguna

N. R. Hinkel

Southwest Research Institute

D. Galán

University of La Laguna

M. Puig-Subirà

Instituto de Astrofísica de Canarias

University of La Laguna

M. Stangret

Instituto de Astrofísica de Canarias

Istituto nazionale di astrofisica (INAF)

University of La Laguna

A. Fukui

University of Tokyo

Instituto de Astrofísica de Canarias

T. Kagetani

University of Tokyo

Norio Narita

National Institutes of Natural Sciences

University of Tokyo

Instituto de Astrofísica de Canarias

D. R. Ciardi

National Aeronautics and Space Administration (NASA)

A. W. Boyle

National Aeronautics and Space Administration (NASA)

C. Ziegler

Stephen F. Austin State University

C. Briceño

Cerro Tololo Inter American Observatory

N. Law

The University of North Carolina System

A. Mann

The University of North Carolina System

Jon M. Jenkins

NASA Ames Research Center

D. W. Latham

Harvard-Smithsonian Center for Astrophysics

Samuel N. Quinn

Harvard-Smithsonian Center for Astrophysics

George R. Ricker

Massachusetts Institute of Technology (MIT)

S. Seager

Massachusetts Institute of Technology (MIT)

Avi Shporer

University College London (UCL)

Eric B. Ting

NASA Ames Research Center

Roland K. Vanderspek

Massachusetts Institute of Technology (MIT)

J. N. Winn

Princeton University

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 668 A158

Subject Categories

Astronomy, Astrophysics and Cosmology

Ocean and River Engineering

Other Physics Topics

DOI

10.1051/0004-6361/202244459

More information

Latest update

3/6/2024 1