Spin detection using RV. All these clusters have 90° inclination. First row: variation of ΔV across various PA. The fitted sin curve is shown in orange, while the grey bar shows the PA_peak. Second row: spatial positions (Δl,Δb) of the stars coloured according to their RV. The identified spin axis (corresponding to PA_peak) is shown in grey. Third row: variation of RV_corr with XR. The red curve shows the rolling average of the RV_corr values.