SOPHIE and SPIRou data of Gl 205. Left: RV time series of Gl 205 from SOPHIE in blue and SPIRou in red with an offset equal to the mean RV of each instrument, RV_SOPHIE = 8727.8 m s⁻¹ and RV_SPIRou = 9345.5 m s⁻¹. The scatter in the time series is 4.7 m s⁻¹ in the SPIRou data set and 4.8 m s⁻¹ in SOPHIE. The labels above the time series depict the four subsets of observations described in Sect. 6. Right: GLS periodogram of the full RV time series, combining SOPHIE and SPIRou observations. The highest peak is marked with an arrow at 34.3 days.