Temporal evolution of the bolometric (blue), X-ray (green), and EUV luminosity (brown) of a 1 M_⊙ star as assumed in our model. The bolometric luminosity is divided by a factor 1000 to bring it on a similar scale as L_X and L_EUV. The two black bars near 4.5 Gyr show the range of our Sun’s L_X over the course of a solar cycle. The grey dashed lines show for comparison the L_X of Tu et al. (2015) for the 10th, 50th, and 90th percentiles of the rotational distribution.