Sub-stellar companions of intermediate-mass stars with CoRoT: CoRoT-34b, CoRoT-35b, and CoRoT-36b
Journal article, 2022
Theories of planet formation give contradicting results of how frequent close-in giant planets of intermediate mass stars (IMSs; 1.3 <= M-* <= 3.2 M-circle dot) are. Some theories predict a high rate of IMSs with close-in gas giants, while others predict a very low rate. Thus, determining the frequency of close-in giant planets of IMSs is an important test for theories of planet formation. We use the CoRoT survey to determine the absolute frequency of IMSs that harbour at least one close-in giant planet and compare it to that of solar-like stars. The CoRoT transit survey is ideal for this purpose, because of its completeness for gas-giant planets with orbital periods of less than 10 d and its large sample of main-sequence IMSs. We present a high precision radial velocity follow-up programme and conclude on 17 promising transit candidates of IMSs, observed with CoRoT. We report the detection of CoRoT-34b, a brown dwarf close to the hydrogen burning limit, orbiting a 1.1 Gyr A-type main-sequence star. We also confirm two inflated giant planets, CoRoT-35b, part of a possible planetary system around a metal-poor star, and CoRoT-36b on a misaligned orbit. We find that 0.12 +/- 0.10 per cent of IMSs between 1.3 <= M-* <= 1.6 M-circle dot observed by CoRoT do harbour at least one close-in giant planet. This is significantly lower than the frequency (0.70 +/- 0.16 per cent) for solar-mass stars, as well as the frequency of IMSs harbouring long-period planets (similar to 8 per cent).
stars: statistics
techniques: photometric
stars: early-type
techniques: radial velocities
Author
D. Sebastian
University of Birmingham
E. W. Guenther
Thüringer Landessternwarte Tautenburg
M. Deleuil
Laboratoire d'Astrophysique de Marseille
M. Dorsch
University of Erlangen-Nuremberg (FAU)
U. Heber
University of Erlangen-Nuremberg (FAU)
C. Heuser
University of Erlangen-Nuremberg (FAU)
D. Gandolfi
Istituto nazionale di astrofisica (INAF)
S. Grziwa
University of Cologne
H. J. Deeg
Instituto de Astrofísica de Canarias
R. Alonso
University of La Laguna
Instituto de Astrofísica de Canarias
F. Bouchy
University of Geneva
Sz Csizmadia
Technische Universität Berlin
F. Cusano
Istituto nazionale di astrofisica (INAF)
Malcolm Fridlund
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Leiden University
S. Geier
University of Potsdam
A. Irrgang
University of Erlangen-Nuremberg (FAU)
Judith Korth
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
D. Nespral
Instituto de Astrofísica de Canarias
University of La Laguna
H. Rauer
Freie Universität Berlin
German Aerospace Center (DLR)
L. Tal-Or
Ariel University
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 516 1 636-655Subject Categories
Astronomy, Astrophysics and Cosmology
DOI
10.1093/mnras/stac2131