A Radial Velocity Study of the Planetary System of π Mensae: Improved Planet Parameters for pi Mensae c and a Third Planet on a 125 Day Orbit
Journal article, 2022

π Men hosts a transiting planet detected by the Transiting Exoplanet Survey Satellite space mission and an outer planet in a 5.7 yr orbit discovered by radial velocity (RV) surveys. We studied this system using new RV measurements taken with the HARPS spectrograph on ESO's 3.6 m telescope, as well as archival data. We constrain the stellar RV semiamplitude due to the transiting planet, π Men c, as K c = 1.21 ± 0.12 m s-1, resulting in a planet mass of M c = 3.63 ± 0.38 M. A planet radius of R c = 2.145 ± 0.015 R yields a bulk density of ρ c = 2.03 ± 0.22 g cm-3. The precisely determined density of this planet and the brightness of the host star make π Men c an excellent laboratory for internal structure and atmospheric characterization studies. Our HARPS RV measurements also reveal compelling evidence for a third body, π Men d, with a minimum mass M d sin i d = 13.38 ± 1.35 M orbiting with a period of P orb,d = 125 days on an eccentric orbit (e d = 0.22). A simple dynamical analysis indicates that the orbit of π Men d is stable on timescales of at least 20 Myr. Given the mutual inclination between the outer gaseous giant and the inner rocky planet and the presence of a third body at 125 days, π Men is an important planetary system for dynamical and formation studies.

Author

A. Hatzes

University of Turin

D. Gandolfi

University of Turin

Judith Korth

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

F. Rodler

European Southern Observatory Santiago

S. Sabotta

Heidelberg-Königstuhl State Observatory

M. Esposito

Thüringer Landessternwarte Tautenburg

O. Barragán

University of Oxford

Vincent Van Eylen

University College London (UCL)

J.H. Livingston

University of Tokyo

L. M. Serrano

University of Turin

R. Luque

Institute of Astrophysics of Andalusia (IAA)

Alexis M. S. Smith

German Aerospace Center (DLR)

S. Redfield

Wesleyan University

Carina Persson

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

Martin Pätzold

University of Cologne

Enric Palle

University of La Laguna

Instituto de Astrofísica de Canarias

G. Nowak

University of La Laguna

Instituto de Astrofísica de Canarias

H. L.M. Osborne

University College London (UCL)

Norio Narita

National Astronomical Observatory of Japan

Japan Science and Technology Agency

Instituto de Astrofísica de Canarias

University of Tokyo

National Institutes of Natural Sciences

S. Mathur

University of La Laguna

Instituto de Astrofísica de Canarias

K. W.F. Lam

Technische Universität Berlin

Petr Kabath

Czech Academy of Sciences

M.C. Johnson

Las Cumbres Observatory Global Telescope Network

E. W. Guenther

Thüringer Landessternwarte Tautenburg

S. Grziwa

University of Cologne

E. Goffo

University of Turin

Malcolm Fridlund

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

Leiden University

M. Endl

The University of Texas at Austin

H. Deeg

Instituto de Astrofísica de Canarias

University of La Laguna

Szilárd Csizmadia

German Aerospace Center (DLR)

William D. Cochran

The University of Texas at Austin

Lucá Gonzalez Cuesta

University of La Laguna

Instituto de Astrofísica de Canarias

Priyanka Chaturvedi

Thüringer Landessternwarte Tautenburg

Ilaria Carleo

Wesleyan University

J. Cabrera

German Aerospace Center (DLR)

P. G. Beck

University of Graz

Simon Albrecht

Aarhus University

Astronomical Journal

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

Vol. 163 5 223

Exoplanets from space -CHEOPS and PLATO ESA's next two projects (Phase 2)

Swedish National Space Board (177/19), 2020-01-01 -- 2022-12-31.

Swedish National Space Board (65/19), 2020-01-01 -- 2022-12-31.

Subject Categories

Astronomy, Astrophysics and Cosmology

Other Physics Topics

Condensed Matter Physics

DOI

10.3847/1538-3881/ac5dcb

More information

Latest update

1/20/2023