The Transiting Multi-planet System HD 3167: A 5.7 M ⊕ Super-Earth and an 8.3 M ⊕ Mini-Neptune
Journal article, 2017

HD 3167 is a bright (V = 8.9 mag) K0 V star observed by NASA’s K2 space mission during its Campaign 8. It has recently been found to host two small transiting planets, namely, HD 3167b, an ultra-short-period (0.96 days) super-Earth, and HD 3167c, a mini-Neptune on a relatively long-period orbit (29.85 days). Here we present an intensive radial velocity (RV) follow-up of HD 3167 performed with the FIES@NOT, HARPS@ESO-3.6 m, and HARPS-N@TNG spectrographs. We revise the system parameters and determine radii, masses, and densities of the two transiting planets by combining the K2 photometry with our spectroscopic data. With a mass of 5.69 ± 0.44 M⊕, a radius of 1.574 ± 0.054 R⊕, and a mean density of {8.00}-0.98+1.10 g cm^-3, HD 3167b joins the small group of ultra-short-period planets known to have rocky terrestrial compositions. HD 3167c has a mass of 8.33-1.85+1.79 M⊕ and a radius of 2.74}-0.100+0.106 R⊕, yielding a mean density of 2.21-0.53+0.56 g cm^-3, indicative of a planet with a composition comprising a solid core surrounded by a thick atmospheric envelope. The rather large pressure scale height (∼350 km) and the brightness of the host star make HD 3167c an ideal target for atmospheric characterization via transmission spectroscopy across a broad range of wavelengths. We found evidence of additional signals in the RV measurements but the currently available data set does not allow us to draw any firm conclusions on the origin of the observed variation.

HD 3167c

planets and satellites: detection

planets and satellites: individual: HD 3167b

stars: fundamental parameters

stars: individual: HD 3167

Author

Davide Gandolfi

University of Turin

Oscar Barragán

University of Turin

Artie P. Hatzes

Thüringer Landessternwarte Tautenburg

Malcolm Fridlund

Astronomy and Plasmaphysics

Luca Fossati

Institut fur Weltraumforschung

Paolo Donati

Arcetri Astrophysical Observatory

Marshall C. Johnson

Ohio State University

Grzegorz Nowak

University of La Laguna

Instituto Astrofisico de Canarias

Jorge Prieto-Arranz

University of La Laguna

Instituto Astrofisico de Canarias

Simon Albrecht

Aarhus University

Fei Dai

Massachusetts Institute of Technology (MIT)

Princeton University

Hans Deeg

Instituto Astrofisico de Canarias

University of La Laguna

Michael Endl

The University of Texas at Austin

Sascha Grziwa

University of Cologne

Maria Hjorth

Aarhus University

Judith Korth

University of Cologne

David Nespral

Instituto Astrofisico de Canarias

University of La Laguna

Joonas Saario

Nordic Optical Telescope

Alexis M. S. Smith

German Aerospace Center (DLR)

Giuliano Antoniciello

University of Turin

Javier Alarcon

European Southern Observatory Santiago

Megan Bedell

University of Chicago

Pere Blay

Nordic Optical Telescope

Instituto Astrofisico de Canarias

Stefan S. Brems

Landessternwarte Heidelberg

Juan Cabrera

German Aerospace Center (DLR)

Szilard Csizmadia

German Aerospace Center (DLR)

Felice Cusano

INAF Istituto di Astrofisica Spaziale e Fisica Cosmica, Bologna

William D. Cochran

The University of Texas at Austin

Philipp Eigmüller

German Aerospace Center (DLR)

Anders Erikson

German Aerospace Center (DLR)

González Hernández

University of La Laguna

Instituto Astrofisico de Canarias

Eike W. Guenther

Thüringer Landessternwarte Tautenburg

Teruyuki Hirano

Tokyo Institute of Technology

Alejandro Suárez Mascareño

University of Geneva

Instituto Astrofisico de Canarias

Norio Narita

National Institutes of Natural Sciences

University of Tokyo

National Institutes of Natural Sciences - National Astronomical Observatory of Japan

Enric Palle

Instituto Astrofisico de Canarias

University of La Laguna

Hannu Parviainen

Instituto Astrofisico de Canarias

University of La Laguna

Martin Pätzold

University of Cologne

Carina Persson

Astronomy and Plasmaphysics

Heike Rauer

German Aerospace Center (DLR)

Technische Universität Berlin

Ivo Saviane

European Southern Observatory Santiago

Linda Schmidtobreick

European Southern Observatory Santiago

Vincent Van Eylen

Leiden University

Joshua N. Winn

Princeton University

Olga V. Zakhozhay

Main Astronomical Observatory Nasu

Astronomical Journal

0004-6256 (ISSN) 1538-3881 (eISSN)

Vol. 154 3 123- 123

Exoplanets from space – CHEOPS and PLATO, ESA’s next two projects

Swedish National Space Board, 2017-01-01 -- 2022-12-31.

Subject Categories

Astronomy, Astrophysics and Cosmology

Roots

Basic sciences

DOI

10.3847/1538-3881/aa832a

More information

Latest update

10/12/2018