Simulated time series of light curves with a linear trend. The light curves are sampled with 1000 regularly spaced points over a total time interval ΔT = 4 years. a) Time series with a trend coefficient a = −0.1 mag/ΔT. b) Same as top panel, but with a = −1.0 mag/ΔT. c) Same as middle panel, but with a sine of period 90 days and amplitude 0.1 mag added to the time series. Noise is added in all the time series with a Gaussian-distributed amplitude of 0.1 mag. The β parameter of the trend (Eq. (4)), the Abbe value of the detrended component of the time series, and the resulting values of and (computed with ΔT_sub = 100 d) are indicated at the top of each panel.