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.
planets and satellites: detection
planets and satellites: individual: HD 3167b
stars: individual: HD 3167
HD 3167c
stars: fundamental parameters
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 de Astrofísica de Canarias
Jorge Prieto-Arranz
University of La Laguna
Instituto de Astrofísica de Canarias
Simon Albrecht
Aarhus University
Fei Dai
Princeton University
Massachusetts Institute of Technology (MIT)
Hans Deeg
University of La Laguna
Instituto de Astrofísica de Canarias
Michael Endl
The University of Texas at Austin
Sascha Grziwa
University of Cologne
Maria Hjorth
Aarhus University
Judith Korth
University of Cologne
David Nespral
University of La Laguna
Instituto de Astrofísica de Canarias
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
Instituto de Astrofísica de Canarias
Nordic Optical Telescope
Stefan S. Brems
Heidelberg-Königstuhl State Observatory
Juan Cabrera
German Aerospace Center (DLR)
Szilard Csizmadia
German Aerospace Center (DLR)
Felice Cusano
Istituto nazionale di astrofisica (INAF)
William D. Cochran
The University of Texas at Austin
Philipp Eigmüller
German Aerospace Center (DLR)
Anders Erikson
German Aerospace Center (DLR)
González Hernández
Instituto de Astrofísica de Canarias
University of La Laguna
Eike W. Guenther
Thüringer Landessternwarte Tautenburg
Teruyuki Hirano
Tokyo Institute of Technology
Alejandro Suárez Mascareño
University of Geneva
Instituto de Astrofísica de Canarias
Norio Narita
National Astronomical Observatory of Japan
National Institutes of Natural Sciences
University of Tokyo
Enric Palle
University of La Laguna
Instituto de Astrofísica de Canarias
Hannu Parviainen
University of La Laguna
Instituto de Astrofísica de Canarias
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- 123Exoplanets from space – CHEOPS and PLATO, ESA’s next two projects
Swedish National Space Board (174/18), 2017-01-01 -- 2022-12-31.
Subject Categories
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
DOI
10.3847/1538-3881/aa832a