Multifractal detrended moving average analysis of Kepler stars with surface differential rotation traces
arXiv:1906.11911 · doi:10.1093/mnras/stz1791
Abstract
A multifractal formalism is employed to analyse high-precision time-series data of \textit{Kepler} stars with surface differential rotation traces. The multifractal detrended moving average analysis (MFDMA) algorithm has been explored to characterize the multi-scale behaviour of the observed time series from a sample of 662 stars selected with parameters close to those of the Sun, e.g., effective temperature, mass, effective gravity and rotation period. Among these stars, 141 have surface differential rotation traces, whereas 521 have no detected differential rotation signatures. In our sample, we also include the Sun in its active phase. Our results can be summarized in two points: first, our work suggests that starspots for time series with and without differential rotation have distinct dynamics, and second, 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 differential rotation is distributed in two regimes segregated by the degree of asymmetry , where -index denotes the global Hurst exponent which 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 differential rotation 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.
arXiv comment27 pages, 1 table., 20 figures, accepted to MNRAS
References in corpus (28)
- Multifractal detrended fluctuation analysis of nonstationary time series
- Multifractality in Human Heartbeat Dynamics
- Kepler Mission Design, Realized Photometric Performance, and Early Science
- Overview of the Kepler Science Processing Pipeline
- Detrending moving average algorithm for multifractals
- Rotation and differential rotation of active Kepler stars
- Multifractal Detrended Fluctuation Analysis of Sunspot Time Series
- Initial Characteristics of Kepler Long Cadence Data For Detecting Transiting Planets
- Selection, Prioritization, and Characteristics of Kepler Target Stars
- A Revised Effective Temperature Scale for the Kepler Input Catalog
- Photometric Variability in Kepler Target Stars. II. An Overview of Amplitude, Periodicity, and Rotation in First Quarter Data
- Testing the recovery of stellar rotation signals from Kepler light curves using a blind hare-and-hounds exercise
- Detecting and interpreting distortions in hierarchical organization of complex time series
- Photometric Variability in Kepler Target Stars. III. Comparison with the Sun on Different Timescales
- The rotation of field stars from CoRoT data
- Kepler Mission Stellar and Instrument Noise Properties Revisited
- Measuring stellar differential rotation with high-precision space-borne photometry
- Differential rotation and meridional flow on the lower zero age main sequence: Reynolds stress versus baroclinic flow
- Overview of semi-sinusoidal stellar variability with the CoRoT satellite
- Nonlinear Time Series Analysis of Sunspot Data
- Multifractality due to long-range correlation in the L-band ionospheric scintillation S4 index time series
- Multifractal Analysis of the Interstellar Medium. First application to Hi-GAL Observations
- Nonextensivity in the solar magnetic activity during the increasing phase of solar Cycle 23
- New Suns in the Cosmos III: multifractal signature analysis
- New Suns in the Cosmos?
- New Suns in the Cosmos IV: the multifractal nature of stellar magnetic activity in \textit{Kepler} cool stars
- New Suns in the Cosmos II: Differential rotation in Kepler Sun-like stars
- Nonextensive triplet in geological faults system