RV (O −C) of asteroids measured at different epochs from 2007 to 2011 as a function of time. Some runs have produced better quality measurements and show a lower dispersion. The red diamonds and error bars represent the weighted mean per run and its uncertainty (values reported in Table 2). The horizontal line marks the offset of 38 m s⁻¹ applied to the catalogue to set its ZP on the asteroid scale.