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In the present study, we investigate the multifractal nature of a long-cadence time series observed by the textit{Kepler} mission for a sample of 34 M dwarf stars and the Sun in its active phase. Using the Multifractal Detrending Moving Average algorithm (MFDMA), which enables the detection of multifractality in nonstationary time series, we define a set of multifractal indices based on the multifractal spectrum profile as a measure of the level of stellar magnetic activity. This set of indices is given by the ($A$,$Delta alpha$,$C$,$H$)-quartet, where $A$, $Delta alpha$ and $C$ are related to geometric features from the multifractal spectrum and the global Hurst exponent $H$ describes the global structure and memorability of time series dynamics. As a test, we measure these indices and compare them with a magnetic index defined as $S_{ph}$ and verify the degree of correlation among them. First, we apply the Poincare plot method and find a strong correlation between the $leftlangle S_{ph}rightrangle$ index and one of the descriptors that emerges from this method. As a result, we find that this index is strongly correlated with long-term features of the signal. From the multifractal perspective, the $leftlangle S_{ph}rightrangle$ index is also strongly linked to the geometric properties of the multifractal spectrum except for the $H$ index. Furthermore, our results emphasize that the rotation period of stars is scaled by the $H$ index, which is consistent with Skumanichs relationship. Finally, our approach suggests that the $H$ index may be related to the evolution of stellar angular momentum and a stars magnetic properties.
In the present study, high-precision time series photometry for the active emph{Kepler} stars is described in the language of multifractals. We explore the potential of using the rescaled range analysis ($R/S$) and multifractal detrended moving avera
In present paper, we investigate the multifractality signatures in hourly time series extracted from CoRoT spacecraft database. Our analysis is intended to highlight the possibility that astrophysical time series can be members of a particular class
The present study reports the discovery of Sun-like stars, namely main-sequence stars with $T_{rm eff}$, $log g$ and rotation periods $P_{rot}$ similar to solar values, presenting evidence of surface differential rotation. An autocorrelation of the t
The present work reports on the discovery of three stars that we have identified to be rotating Sun-like stars, based on rotational modulation signatures inferred from light curves from the CoRoT missions Public Archives. In our analysis, we performe
In this splinter session, ten speakers presented results on solar and stellar activity and how the two fields are connected. This was followed by a lively discussion and supplemented by short, one-minute highlight talks. The talks presented new theor