Optical and near-infrared stellar activity characterization of the early M dwarf Gl 205 with SOPHIE and SPIRou

Autor: P. Cortés-Zuleta, I. Boisse, B. Klein, E. Martioli, P. I. Cristofari, A. Antoniadis-Karnavas, J.-F. Donati, X. Delfosse, C. Cadieux, N. Heidari, É. Artigau, S. Bellotti, X. Bonfils, A. Carmona, N. J. Cook, R. F. Díaz, R. Doyon, P. Fouqué, C. Moutou, P. Petit, T. Vandal, L. Acuña, L. Arnold, N. Astudillo-Defru, V. Bourrier, F. Bouchy, R. Cloutier, S. Dalal, M. Deleuil, O. D. S. Demangeon, X. Dumusque, T. Forveille, J. Gomes da Silva, N. Hara, G. Hébrard, S. Hoyer, G. Hussain, F. Kiefer, J. Morin, A. Santerne, N. C. Santos, D. Segransan, M. Stalport, S. Udry
Rok vydání: 2023
Předmět:
Zdroj: Astronomy & Astrophysics. 673:A14
ISSN: 1432-0746
0004-6361
DOI: 10.1051/0004-6361/202245131
Popis: The stellar activity of M dwarfs is the main limitation for discovering and characterizing exoplanets orbiting them since it induces quasi-periodic RV variations. We aim to characterize the magnetic field and stellar activity of the early, moderately active, M dwarf Gl205 in the optical and nIR domains. We obtained high-precision quasi-simultaneous spectra in the optical and nIR with the SOPHIE spectrograph and SPIRou spectropolarimeter between 2019 and 2022. We computed the RVs from both instruments and the SPIRou Stokes V profiles. We used ZDI to map the large-scale magnetic field over the time span of the observations. We studied the temporal behavior of optical and nIR RVs and activity indicators with the Lomb-Scargle periodogram and a quasi-periodic GP regression. In the nIR, we studied the equivalent width of Al I, Ti I, K I, Fe I, and He I. We modeled the activity-induced RV jitter using a multi-dimensional GP regression with activity indicators as ancillary time series. The optical and nIR RVs have similar scatter but nIR shows a more complex temporal evolution. We observe an evolution of the magnetic field topology from a poloidal dipolar field in 2019 to a dominantly toroidal field in 2022. We measured a stellar rotation period of Prot=34.4$\pm$0.5 d in the longitudinal magnetic field. Using ZDI we measure the amount of latitudinal differential rotation (DR) shearing the stellar surface yielding rotation periods of Peq=32.0$\pm$1.8 d at the stellar equator and Ppol=45.5$\pm$0.3 d at the poles. We observed inconsistencies in the activity indicators' periodicities that could be explained by these DR values. The multi-dimensional GP modeling yields an RMS of the RV residuals down to the noise level of 3 m/s for both instruments, using as ancillary time series H$\alpha$ and the BIS in the optical, and the FWHM in the nIR.
Comment: 41 pages, 24 figures. Accepted for publication in A&A. Improved quality of figures and reduced size of Appendix
Databáze: OpenAIRE
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