Four examples of the natural logarithm of literature-reported stellar age as a function of FUV-excess parameter Q for field stars only. The red line indicates the refined fit to combined stars from the four catalogs. Parameters of these fits can be found in the upper half of Table 2. Fits are restricted to stars with ﹩Q\lesssim -1.0﹩, which depends on the flattening of the data in each (B − V) range. Symbols denote stellar metal abundance according to the convention ﹩-0.8\leqslant [\mathrm{Fe}/{\rm{H}}]\lt -0.2﹩ (circles), ﹩-0.2\leqslant [\mathrm{Fe}/{\rm{H}}]\lt 0.1﹩ (triangles), ﹩0.1\leqslant [\mathrm{Fe}/{\rm{H}}]\lt 0.5﹩ (diamonds), or no metallicity estimate quoted in Cassagrande (2011; stars).