Kepler stars' surface differential rotation

First, our work suggests that star-spots for time series with and without DR have distinct dynamics. Secondly, the magnetic fields of active stars are apparently governed by two mechanisms with different levels of complexity for fluctuations. Throughout the course of the study, we identified an overall trend whereby the DR is distributed in two H regimes segregated by the degree of asymmetry A, where H-index denotes the global Hurst exponent that is used as a measure of long-term memory of time series.

As a result, we show that the degree of asymmetry can be considered a segregation factor that distinguishes the DR behaviour when related to the effect of the rotational modulation on the time series. In summary, the multifractality signals in our sample are the result of magnetic activity control mechanisms leading to activity-related long-term persistent signatures.