TOI-674b: An oasis in the desert of exo-Neptunes transiting a nearby M dwarf
Journal article, 2021

Context. The NASA mission TESS is currently doing an all-sky survey from space to detect transiting planets around bright stars. As part of the validation process, the most promising planet candidates need to be confirmed and characterized using follow-up observations. Aims. In this article, our aim is to confirm the planetary nature of the transiting planet candidate TOI-674b using spectroscopic and photometric observations. Methods. We use TESS, Spitzer, ground-based light curves, and HARPS spectrograph radial velocity measurements to establish the physical properties of the transiting exoplanet candidate TOI-674b. We perform 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 TOI-674b, a low-density super-Neptune transiting a nearby M dwarf. The host star (TIC 158588995, V = 14.2 mag, J = 10.3 mag) is characterized by its M2V spectral type with M = 0.420 ± 0.010 M , R = 0.420 ± 0.013 R , and Teff = 3514 ± 57 K; it is located at a distance d = 46.16 ± 0.03 pc. Combining the available transit light curves plus radial velocity measurements and jointly fitting a circular orbit model, we find an orbital period of 1.977143 ± 3 × 10-6 days, a planetary radius of 5.25 ± 0.17 R , and a mass of 23.6 ± 3.3 M implying a mean density of ρp =0.91 ± 0.15 g cm-3. A non-circular orbit model fit delivers similar planetary mass and radius values within the uncertainties. Given the measured planetary radius and mass, TOI-674b is one of the largest and most massive super-Neptune class planets discovered around an M-type star to date. It is found in the Neptunian desert, and is a promising candidate for atmospheric characterization using the James Webb Space Telescope.

Stars: individual: TOI-674

Techniques: photometric

Techniques: radial velocities

Planets and satellites: gaseous planets

Planets and satellites: general

Author

F. Murgas

University of La Laguna

Instituto Astrofisico de Canarias

N. Astudillo-Defru

Universidad Catolica de la Santisima Concepcion

X. Bonfils

Grenoble Alpes University

I. J.M. Crossfield

University of Kansas

J. M. Almenara

Grenoble Alpes University

J.H. Livingston

University of Tokyo

Keivan G. Stassun

Vanderbilt University

Judith Korth

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Extragalactic Astrophysics

J. Orell-Miquel

University of La Laguna

Instituto Astrofisico de Canarias

Giuseppe Morello

Instituto Astrofisico de Canarias

University of La Laguna

J. D. Eastman

Harvard-Smithsonian Center for Astrophysics

Jack J. Lissauer

NASA Ames Research Center

S. R. Kane

University of California

F. Y. Morales

Jet Propulsion Laboratory, California Institute of Technology

M. W. Werner

Universidad Catolica de la Santisima Concepcion

V. Gorjian

Universidad Catolica de la Santisima Concepcion

B. Benneke

Université de Montréal

D. Dragomir

University of New Mexico

Elisabeth Matthews

University of Geneva

S.B. Howell

NASA Ames Research Center

D. R. Ciardi

California Institute of Technology (Caltech)

Erica J. Gonzales

University of California

Rachel A. Matson

US Naval Observatory

C. Beichman

California Institute of Technology (Caltech)

Joshua E. Schlieder

NASA Goddard Space Flight Center

Karen A. Collins

Harvard-Smithsonian Center for Astrophysics

Kevin I. Collins

George Mason University

Eric L.N. Jensen

Swarthmore College

P. Evans

El Sauce Observatory

Francisco J. Pozuelos

University of Liège

Michaël Gillon

University of Liège

Emmanuel Jehin

University of Liège

Khalid Barkaoui

Universite Cadi Ayyad

University of Liège

E. Artigau

Consejo Nacional de Investigaciones Cientificas y Tecnicas

F. Bouchy

University of Geneva

D. Charbonneau

Harvard-Smithsonian Center for Astrophysics

X. Delfosse

Grenoble Alpes University

R. F. Diaz

Consejo Nacional de Investigaciones Cientificas y Tecnicas

René Doyon

Université de Montréal

P. Figueira

European Southern Observatory Santiago

University of Porto

T. Forveille

Grenoble Alpes University

C. Lovis

University of Geneva

C. Melo

European Southern Observatory Santiago

G. Gaisné

Grenoble Alpes University

Francesco Pepe

University of Geneva

N. C. Santos

University of Porto

D. Segransan

University of Geneva

S. Udry

University of Geneva

Robert Goeke

Massachusetts Institute of Technology (MIT)

A. M. Levine

Massachusetts Institute of Technology (MIT)

E. V. Quintana

NASA Goddard Space Flight Center

N. Guerrero

Massachusetts Institute of Technology (MIT)

Ismael Mireles

Massachusetts Institute of Technology (MIT)

D. A. Caldwell

SETI Institute

NASA Ames Research Center

P. Tenenbaum

SETI Institute

NASA Ames Research Center

C. E. Brasseur

Space Telescope Science Institute (STScI)

George R. Ricker

Massachusetts Institute of Technology (MIT)

Roland K. Vanderspek

Massachusetts Institute of Technology (MIT)

D. W. Latham

Harvard-Smithsonian Center for Astrophysics

S. Seager

Massachusetts Institute of Technology (MIT)

J. N. Winn

Princeton University

Jon M. Jenkins

NASA Ames Research Center

Astronomy and Astrophysics

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

Vol. 653 A60

Subject Categories

Astronomy, Astrophysics and Cosmology

Ocean and River Engineering

Other Physics Topics

DOI

10.1051/0004-6361/202140718

More information

Latest update

9/20/2021