ΔRV values (difference between the measured spectroscopic RVs and the astrometric RVs, with GR and CB removed) shown as a function of R.A. for 135 stars in the Hyades. The dashed line is a least-squares fit, giving a slope of 0.0228 ± 0.0017 km s⁻¹ deg⁻¹. The Pearson correlation coefficient is 0.35 (p value = 3 × 10⁻⁵). For the interpretation of this trend, see the text.