HD 89345: A bright oscillating star hosting a transiting warm Saturn-sized planet observed by K2
Artikel i vetenskaplig tidskrift, 2018
We report the discovery and characterization of HD 89345b (K2-234b; EPIC 248777106b), a Saturn-sized planet orbiting a slightly evolved star. HD 89345 is a bright star (V = 9.3 mag) observed by the K2 mission with 1 min time sampling. It exhibits solar-like oscillations. We conducted asteroseismology to determine the parameters of the star, finding themass and radius to be 1.12-0.01+0.04M⊙and 1.657-0.004+0.020R⊙, respectively. The star appears to have recently left the main sequence, based on the inferred age, 9.4-1.3+0.4Gyr, and the non-detection of mixed modes. The star hosts a 'warm Saturn' (P = 11.8 d, Rp= 6.86 ± 0.14 R⊕). Radial-velocity follow-up observations performed with the FIbre-fed Echelle Spectrograph, HARPS, and HARPS-N spectrographs show that the planet has a mass of 35.7 ± 3.3 M⊕. The data also show that the planet's orbit is eccentric (e≈0.2). An investigation of the rotational splitting of the oscillation frequencies of the star yields no conclusive evidence on the stellar inclination angle. We further obtained Rossiter-McLaughlin observations, which result in a broad posterior of the stellar obliquity. The planet seems to confirm to the same patterns that have been observed for other sub-Saturns regarding planet mass and multiplicity, orbital eccentricity, and stellar metallicity.
Planets and satellites: formation
Asteroseismology
Planets and satellites: fundamental parameters
Planets and satellites: composition
Författare
Vincent Van Eylen
Universiteit Leiden
Fei Dai
Princeton University
Massachusetts Institute of Technology (MIT)
S. Mathur
Instituto de Astrofísica de Canarias
Universidad de la Laguna
D. Gandolfi
Universita degli Studi di Torino
Simon Albrecht
Aarhus Universitet
Malcolm Fridlund
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Universiteit Leiden
R. A. García
Université Paris-Saclay
Le Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA)
E. W. Guenther
Thüringer Landessternwarte Tautenburg
M. Hjorth
Aarhus Universitet
A.B. Justesen
Aarhus Universitet
J.H. Livingston
University of Tokyo
M. N. Lund
Aarhus Universitet
F. Pérez Hernández
Universidad de la Laguna
Instituto de Astrofísica de Canarias
J. Prieto-Arranz
Universidad de la Laguna
Instituto de Astrofísica de Canarias
C. Regulo
Universidad de la Laguna
Instituto de Astrofísica de Canarias
L. Bugnet
Le Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA)
Université Paris-Saclay
M.E. Everett
National Optical Astronomy Observatory
T. Hirano
Tokyo Institute of Technology
David Nespral
Instituto de Astrofísica de Canarias
Universidad de la Laguna
G. Nowak
Universidad de la Laguna
Instituto de Astrofísica de Canarias
E. Palle
Universidad de la Laguna
Instituto de Astrofísica de Canarias
V. Silva Aguirre
Aarhus Universitet
T. Trifonov
Max-Planck-Gesellschaft
J. N. Winn
Princeton University
O. Barragán
Universita degli Studi di Torino
P. G. Beck
Instituto de Astrofísica de Canarias
Universidad de la Laguna
W. J. Chaplin
Aarhus Universitet
University of Birmingham
William D. Cochran
The University of Texas at Austin
Szilard Csizmadia
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
H. Deeg
Instituto de Astrofísica de Canarias
Universidad de la Laguna
M. Endl
The University of Texas at Austin
P. Heeren
Landessternwarte Heidelberg-Königstuhl
S. Grziwa
Universität zu Köln
A. Hatzes
Thüringer Landessternwarte Tautenburg
D. Hidalgo
Instituto de Astrofísica de Canarias
Universidad de la Laguna
Judith Korth
Universität zu Köln
S. Mathis
Université Paris-Saclay
Le Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA)
P. Montanés Rodríguez
Universidad de la Laguna
Instituto de Astrofísica de Canarias
Norio Narita
National Institutes of Natural Sciences
University of Tokyo
Martin Pätzold
Universität zu Köln
Carina Persson
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
F. Rodler
European Southern Observatory Santiago
Alexis M. S. Smith
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 478 4 4866-4880Exoplaneter från rymden - CHEOPS och PLATO, ESA's nästa två missioner
Rymdstyrelsen (174/18), 2017-01-01 -- 2022-12-31.
Ämneskategorier
Meteorologi och atmosfärforskning
Astronomi, astrofysik och kosmologi
Bioinformatik (beräkningsbiologi)
Infrastruktur
Onsala rymdobservatorium
DOI
10.1093/mnras/sty1390