| Issue |
A&A
Volume 678, October 2023
|
|
|---|---|---|
| Article Number | A207 | |
| Number of page(s) | 23 | |
| Section | Planets and planetary systems | |
| DOI | https://doi.org/10.1051/0004-6361/202346813 | |
| Published online | 30 October 2023 | |
Characterizing planetary systems with SPIRou: M-dwarf planet-search survey and the multiplanet systems GJ 876 and GJ 1148★,★★
1
Univ. de Toulouse, CNRS, IRAP,
14 avenue Belin,
31400
Toulouse, France
e-mail: claire.moutou@irap.omp.eu
2
Univ. Grenoble Alpes, CNRS, IPAG,
38000
Grenoble, France
3
Université Côte d’Azur, Laboratoire Lagrange, OCA, CNRS UMR
7293,
Nice, France
4
Université de Montréal, Département de Physique, IREX,
Montréal, QC
H3C 3J7, Canada
5
Trottier Institute for Research on Exoplanets, Université de Montréal, Département de Physique,
C.P. 6128
Succ. Centre-ville,
Montréal, QC
H3C 3J7, Canada
6
Canada-France-Hawaii Telescope, CNRS,
96743
Kamuela, HI, USA
7
Aix-Marseille Université, CNRS, CNES, LAM (Laboratoire d’Astrophysique de Marseille),
Marseille, France
8
Geneva Observatory, University of Geneva,
Chemin Pegasi 51,
1290
Versoix, Switzerland
9
Institut d’Astrophysique de Paris, UMR7095 CNRS, Université Pierre & Marie Curie,
98 bis boulevard Arago,
75014
Paris, France
10
Laboratorio Nacional de Astrofísica,
Rua Estados Unidos 154,
37504-364,
Itajubá, MG, Brazil
11
Université de Montpellier, CNRS, LUPM,
34095
Montpellier, France
12
Science Division, Directorate of Science, European Space Research and Technology Centre (ESA/ESTEC),
Keplerlaan 1,
2201 AZ,
Noordwijk, The Netherlands
Received:
4
May
2023
Accepted:
3
July
2023
SPIRou is a near-infrared spectropolarimeter and a high-precision velocimeter. The SPIRou Legacy Survey collected data from February 2019 to June 2022, half of the time devoted to a blind search for exoplanets around nearby cool stars. The aim of this paper is to present this program and an overview of its properties, and to revisit the radial velocity (RV) data of two multiplanet systems, including new visits with SPIRou. From SPIRou data, we can extract precise RVs using efficient telluric correction and line-by-line measurement techniques, and we can reconstruct stellar magnetic fields from the collection of polarized spectra using the Zeeman-Doppler imaging method. The stellar sample of our blind search in the solar neighborhood, the observing strategy, the RV noise estimates, chromatic behavior, and current limitations of SPIRou RV measurements on bright M dwarfs are described. In addition, SPIRou data over a 2.5-yr time span allow us to revisit the known multiplanet systems GJ 876 and GJ 1148. For GJ 876, the new dynamical analysis including the four planets is consistent with previous models and confirms that this system is deep in the Laplace resonance and likely chaotic. The large-scale magnetic map of GJ 876 over two consecutive observing seasons is obtained and shows a dominant dipolar field with a polar strength of 30 G, which defines the magnetic environment in which the inner planet with a period of 1.94 days is embedded. For GJ 1148, we refine the known two-planet model.
Key words: stars: low-mass / planetary systems / methods: observational / techniques: radial velocities / techniques: polarimetric / stars: magnetic field
RV time series are available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/678/A207
Based on observations obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l’Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. The observations at the CFHT were performed with care and respect from the summit of Maunakea which is a significant cultural and historic site.
© The Authors 2023
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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