| Issue |
A&A
Volume 696, April 2025
|
|
|---|---|---|
| Article Number | A152 | |
| Number of page(s) | 27 | |
| Section | Planets, planetary systems, and small bodies | |
| DOI | https://doi.org/10.1051/0004-6361/202347814 | |
| Published online | 16 April 2025 | |
The SPIRou Legacy Survey
Near-infrared and optical radial velocity analysis of Gl 480 and Gl 382 using SPIRou, HARPS and CARMENES spectrographs★
1
Université de Toulouse, UPS-OMP, IRAP,
14 avenue E. Belin,
31400
Toulouse,
France
2
Trottier Institute for Research on Exoplanets, Université de Montréal, Département de Physique,
C.P. 6128 Succ. Centre-ville,
Montréal,
QC
H3C 3J7,
Canada
3
Observatoire du Mont-Mégantic, Université de Montréal, Département de Physique,
C.P. 6128 Succ. Centre-ville,
Montréal,
QC
H3C 3J7,
Canada
4
Laboratório Nacional de Astrofísica,
Rua Estados Unidos 154,
37504-364
Itajubá - MG,
Brazil
5
Institut d’Astrophysique de Paris, CNRS, UMR 7095 Sorbonne, France Université,
98 bis bd Arago,
75014
Paris,
France
6
Univ. Grenoble Alpes, CNRS, IPAG,
38000
Grenoble,
France
7
Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas,
4150-762
Porto,
Portugal
8
Center for Astrophysics | Harvard & Smithsonian,
60 Garden Street,
Cambridge,
MA
02138,
USA
9
Department of Physics & Astronomy, McMaster University,
1280 Main Street West,
Hamilton,
ON
L8S 4L8,
Canada
★★ Corresponding author; merwan.ould-elhkim@irap.omp.eu
Received:
28
August
2023
Accepted:
5
February
2025
Context. Advancements in the field of exoplanetary research have extended radial velocity (RV) observations from the optical to the near-infrared (nIR) domain. M dwarf stars, characterized by their lower masses and higher prevalence of rocky planets, have become a focal point of investigation. This study uses data from the nIR spectropolarimeter SPIRou and data available in the literature from the HARPS and CARMENES spectrographs operating in the optical to analyze RVs of two nearby M dwarfs, Gl 480 and Gl 382.
Aims. In this work our aims is to detect and characterize exoplanetary companions around Gl 480 and Gl 382 by mitigating stellar activity effects through advanced data analysis techniques. The study seeks to improve the reliability of RV signals by integrating multi-wavelength observations and stellar activity diagnostics.
Methods. The study employs a comprehensive approach that combines the line-by-line (LBL) framework with the Weighted principAl comPonent analysIs reconsTructIon (Wapiti) method to correct for systematics in SPIRou data. Through an extensive analysis of available stellar activity indicators and by combining optical data from the HARPS and CARMENES instruments, we perform a joint analysis of RV measurements in the nIR and the optical domains.
Results. Our analysis confirms the detection of a planet orbiting Gl 480 with a period of 9.5537 ± 0.0005 d and a minimum mass of 8.8 ± 0.7 M⊕. Additionally, we detect a tentative signal at 6.4 d, whose significance strongly depends on the choice of Gaussian process priors constrained by stellar activity indicators and would require further observations for confirmation. In contrast, no planetary signals are detected for Gl 382, where RV variations are dominated by stellar activity.
Key words: instrumentation: spectrographs / techniques: radial velocities / stars: low-mass / planetary systems / stars: individual: Gl 382 / stars: individual: Gl 480
Based on observations obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated from the summit of Maunakea by the National Research Council of Canada, the Institut National des Sciences de l’Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii. The observations at the Canada-France-Hawaii Telescope were performed with care and respect from the summit of Maunakea which is a significant cultural and historic site. Based on observations obtained with SPIRou, an international project led by Institut de Recherche en Astrophysique et Planétologie, Toulouse, France. SPIRou is an acronym for SPectropolarimetre InfraROUge (infrared spectropolarimeter).
© The Authors 2025
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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