TESS's first planet: A super-Earth transiting the naked-eye star π Mensae
Journal article, 2018
We report on the confirmation and mass determination of π Men c, the first transiting planet discovered by NASA's TESS space mission. π Men is a naked-eye (V = 5.65 mag), quiet G0 V star that was previously known to host a sub-stellar companion (π Men b) on a longperiod (Porb = 2091 days), eccentric (e = 0.64) orbit. Using TESS time-series photometry, combined with Gaia data, published UCLES at AAT Doppler measurements, and archival HARPS at ESO-3.6m radial velocities, we found that π Men c is a close-in planet with an orbital period of Porb = 6.27 days, a mass of Mc = 4.52 ± 0.81 Mo, and a radius of Rc = 2.06 ± 0.03 Ro. Based on the planet's orbital period and size, π Men c is a super-Earth located at, or close to, the radius gap, while its mass and bulk density suggest it may have held on to a significant atmosphere. Because of the brightness of the host star, this system is highly suitable for a wide range of further studies to characterize the planetary atmosphere and dynamical properties. We also performed an asteroseismic analysis of the TESS data and detected a hint of power excess consistent with the seismic values expected for this star, although this result depends on the photometric aperture used to extract the light curve. This marginal detection is expected from pre-launch simulations hinting at the asteroseismic potential of the TESS mission for longer, multi-sector observations and/or for more evolved bright stars.
Planets and satellites: terrestrial planets
Stars: fundamental parameters
Planetary systems
Planets and satellites: fundamental parameters
Planets and satellites: detection
Author
D. Gandolfi
University of Turin
O. Barragán
University of Turin
J.H. Livingston
University of Tokyo
Malcolm Fridlund
Leiden University
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
A.B. Justesen
Aarhus University
S. Redfield
Wesleyan University
L. Fossati
Institut fur Weltraumforschung
S. Mathur
University of La Laguna
Instituto de Astrofísica de Canarias
S. Grziwa
University of Cologne
J. Cabrera
German Aerospace Center (DLR)
R. A. García
Paris Diderot University
University Paris-Saclay
Carina Persson
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Vincent Van Eylen
Princeton University
A. Hatzes
Thüringer Landessternwarte Tautenburg
D. Hidalgo
Instituto de Astrofísica de Canarias
University of La Laguna
Simon Albrecht
Aarhus University
L. Bugnet
Paris Diderot University
University Paris-Saclay
William D. Cochran
The University of Texas at Austin
Szilard Csizmadia
German Aerospace Center (DLR)
H. Deeg
Instituto de Astrofísica de Canarias
University of La Laguna
P. Eigmüller
German Aerospace Center (DLR)
M. Endl
The University of Texas at Austin
Anders Erikson
German Aerospace Center (DLR)
M. Esposito
Thüringer Landessternwarte Tautenburg
E. W. Guenther
Thüringer Landessternwarte Tautenburg
Judith Korth
University of Cologne
R. Luque
University of La Laguna
Instituto de Astrofísica de Canarias
P. M. Rodriguez
Instituto de Astrofísica de Canarias
University of La Laguna
David Nespral
University of La Laguna
Instituto de Astrofísica de Canarias
G. Nowak
Instituto de Astrofísica de Canarias
University of La Laguna
Martin Pätzold
University of Cologne
J. Prieto-Arranz
University of La Laguna
Instituto de Astrofísica de Canarias
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 619 L10Subject Categories
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
DOI
10.1051/0004-6361/201834289