tokens: It is defined as the standard deviation of the differential light curve over each of the five rotations (Mathur et al. 2014 ). In the analyses below, all three of these measures were tried and found to be essentially equivalent for the purpose of correlating brightness with variability. The method actually employed in this paper is the re-sampled fit to the smoothed R loc ; we will call this R smo . This leads to a set of both absolute brightness and variability measurements at the same 45 time points in each light curve. A few illustrations of these sets are provided in the upper panel of Figure 11 . A linear fit is made to each set of points, and both the slope and Pearson-r correlation coefficient are computed. For the small and large red asterisks, the [slope, Pearson-r] values are [−0.14, −0.91] and [−0.92, −0.84]; for the small and large pluses, they are [0.16, 0.87] and [0.59, 0.53]; and for the small and large black diamonds, they are [0.00, 0.01] and [−0.20, −0.30]. The KIC numbers for the stars shown (in the same order) are 5302725, 9334867, 8078753, 11014223, 2694810, and 11299398. Shown in aqua in the lower panel are the 12 stars that MTF17 identified as exhibiting clear activity cycles over 4 years of observations (their Figure 5 ). Four of these are very clear-cut cases of spot dominance (those with the most negative r coefficients and slopes), two are unclear (those above the lower dotted line), and the rest are distributed along a continuum of spot dominance. Figure 11. Upper panel: five illustrative sets of brightness vs. variability. They have been scaled and shifted to fit on the plot. Color and symbol size are related to slope (see text). Lower panel: slopes of the linear fits to the brightness vs. variability points for all stars; the ordinate is the Pearson-r coefficient for each star. The colors indicate the designations from MTF17 based on the sign of their correlation slopes (see text). Green points are stars with clear brightness cycles in MTF17. MTF17 divided the sample into three cases: anti-correlated (red), correlated (blue), and not clear (black); the colors in Figure 11 correspond to their classification. As explained in Section 2.1 , the “anti-correlated” label is used for stars that become brighter as they become more variable; they are generally interpreted to be faculae-dominated. The points for such stars have a positive slope, so they should lie in the upper right quadrant of the lower panel of Figure 11 , which shows the results for the full sample. Similarly, the blue (correlated) stars get darker as they get more variable (spot-dominated) and are in the lower left quadrant. Most stars from the sample (320 in MTF17; 322 for us) are in this category. In most cases (310 stars), their sense agrees with ours, although there are a few red points in the lower left quadrant, and stars that they did not classify in either category (black) are found in both quadrants for us. The most likely source of discrepancies
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