Results of the YORP search for asteroid (85990) 1999 JV6, based on the convex-light-curve-inversion procedures described in Sect. 3.1. For a set of YORP factors a grid of possible pole positions was tested with shape and period optimised at each point. The quality of the fit, χ², was recorded and the smallest value of χ² from each search is plotted here against the YORP factor. Left: full range of YORP factors investigated, right: zoomed-in view of the region around the minimum χ² values. A YORP-induced spin-up of 2 × 10⁻⁸ rad day² gives the best fit to the light-curve data, but the constant period solution cannot be discarded. The horizontal lines mark the increases above the best-fit χ² minimum: + 1% (green) and + 10% (red).