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

DOI: 
10.3847/1538-3881/ac5dcb
Publication date: 
08/05/2022
Main author: 
Hatzes, Artie P.
IAA authors: 
Luque, Rafael
Authors: 
Hatzes, Artie P.;Gandolfi, Davide;Korth, Judith;Rodler, Florian;Sabotta, Silvia;Esposito, Massimiliano;Barragán, Oscar;Van Eylen, Vincent;Livingston, John H.;Serrano, Luisa Maria;Luque, Rafael;Smith, Alexis M. S.;Redfield, Seth;Persson, Carina M.;Pätzold, Martin;Palle, Enric;Nowak, Grzegorz;Osborne, Hannah L. M.;Narita, Norio;Mathur, Savita;Lam, Kristine W. F.;Kabáth, Petr;Johnson, Marshall C.;Guenther, Eike W.;Grziwa, Sascha;Goffo, Elisa;Fridlund, Malcolm;Endl, Michael;Deeg, Hans J.;Csizmadia, Szilard;Cochran, William D.;Cuesta, Lucía González;Chaturvedi, Priyanka;Carleo, Ilaria;Cabrera, Juan;Beck, Paul G.;Albrecht, Simon
Journal: 
The Astronomical Journal
Refereed: 
Yes
Publication type: 
Article
Volume: 
163
Pages: 
223
Abstract: 
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 <SUB>c</SUB> = 1.21 ± 0.12 m s<SUP>-1</SUP>, resulting in a planet mass of M <SUB>c</SUB> = 3.63 ± 0.38 M <SUB>⊕</SUB>. A planet radius of R <SUB>c</SUB> = 2.145 ± 0.015 R <SUB>⊕</SUB> yields a bulk density of ρ <SUB>c</SUB> = 2.03 ± 0.22 g cm<SUP>-3</SUP>. 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 <SUB>d</SUB> sin i <SUB>d</SUB> = 13.38 ± 1.35 M <SUB>⊕</SUB> orbiting with a period of P <SUB>orb,d</SUB> = 125 days on an eccentric orbit (e <SUB>d</SUB> = 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.
Database: 
ADS
SCOPUS
URL: 
https://ui.adsabs.harvard.edu/#abs/2022AJ....163..223H/abstract
ADS Bibcode: 
2022AJ....163..223H
Keywords: 
Exoplanet systems;484;Astrophysics - Earth and Planetary Astrophysics;Astrophysics - Solar and Stellar Astrophysics