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Related papers: Fractal signature as a rotational modulation and s…

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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…

Solar and Stellar Astrophysics · Physics 2019-08-14 D. B. de Freitas , M. M. F. Nepomuceno , L. D. Alves Rios , M. L. Das Chagas , J. R. De Medeiros

Asteroseismology offers the prospect of constraining differential rotation in Sun-like stars. Here we have identified six high signal-to-noise main-sequence Sun-like stars in the Kepler field, which all have visible signs of rotational…

Solar and Stellar Astrophysics · Physics 2014-09-10 M. B. Nielsen , L. Gizon , H. Schunker , J. Schou

We present the results of time-series photometric analysis of 15106 A-K type stars observed by the Kepler space mission. We identified 513 new rotational variables and measured their starspot rotation periods as a function of spectral type…

Solar and Stellar Astrophysics · Physics 2018-12-10 Sowgata Chowdhury , Santosh Joshi , Chris A. Engelbrecht , Peter De Cat , Yogesh. C. Joshi , K. T. Paul

In the Sun, the frequencies of the acoustic modes are observed to vary in phase with the magnetic activity level. These frequency variations are expected to be common in solar-type stars and contain information about the activity-related…

Solar and Stellar Astrophysics · Physics 2018-08-01 A. R. G. Santos , T. L. Campante , W. J. Chaplin , M. S. Cunha , M. N. Lund , R. Kiefer , D. Salabert , R. A. Garcia , G. R. Davies , Y Elsworth , R. Howe

Kepler-30 is a unique target to study stellar activity and rotation in a young solar-like star accompanied by a compact planetary system. We use about 4 years of high-precision photometry collected by the Kepler mission to investigate the…

Solar and Stellar Astrophysics · Physics 2021-06-09 D. B. de Freitas , A. F. Lanza , F. O. da Silva Gomes , M. L. Das Chagas

Gravito-acoustic modes in the Sun and other stars propagate in resonant cavities with a frequency below a given limit known as the cut-off frequency. At higher frequencies, waves are no longer trapped in the stellar interior and become…

Solar and Stellar Astrophysics · Physics 2015-11-04 A. Jimenez , R. A. Garcia , F. Perez Hernandez , S. Mathur

Solar-like oscillations have been observed by Kepler and CoRoT in several solar-type stars, thereby providing a way to probe the stars using asteroseismology. We provide the mode frequencies of the oscillations of various stars required to…

We use high accuracy photometric data obtained with the Kepler satellite to monitor the activity modulations of the Kepler-210 planet host star over a time span of more than four years. Following the phenomenology of the star's light curve…

Solar and Stellar Astrophysics · Physics 2016-10-07 P. Ioannidis , J. H. M. M. Schmitt

We investigate the relation between rotation periods $P_\mathrm{rot}$ and photometric modulation amplitudes $R_\mathrm{per}$ for $\approx 4,000$ Sun-like main-sequence stars observed by Kepler, using $P_\mathrm{rot}$ and $R_\mathrm{per}$…

Solar and Stellar Astrophysics · Physics 2022-07-20 Kento Masuda

Sun-like stars show intensity fluctuations on a number of time scales due to various physical phenomena on their surfaces. These phenomena can convincingly be studied in the frequency spectra of these stars - while the strongest signatures…

Solar and Stellar Astrophysics · Physics 2015-06-15 C. Karoff , T. L. Campante , J. Ballot , T. Kallinger , M. Gruberbauer , R. A. Garcia , D. A. Caldwell , J. L. Christiansen , K. Kinemuchi

The Kepler space telescope leaves a legacy of tens of thousands of stellar rotation period measurements. While many of these stars show strong periodicity, there exists an even bigger fraction of stars with irregular variability for which…

Solar and Stellar Astrophysics · Physics 2023-10-04 Timo Reinhold , Alexander I. Shapiro , Sami K. Solanki , Gibor Basri

For a solar-like star, the surface rotation evolves with time, allowing in principle to estimate the age of a star from its surface rotation period. Here we are interested in measuring surface rotation periods of solar-like stars observed…

Solar and Stellar Astrophysics · Physics 2019-06-25 S. N. Breton , L. Bugnet , A. R. G. Santos , A. Le Saux , S. Mathur , P. L. Palle , R. A. Garcia

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…

Solar and Stellar Astrophysics · Physics 2019-08-07 D. B. de Freitas , M. M. F. Nepomuceno , J. G. Cordeiro , M. L. Das Chagas , J. R. De Medeiros

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…

The plethora of photometric data collected by the Kepler space telescope has promoted the detection of tens of thousands of stellar rotation periods. However, these periods are not found to an equal extent among different spectral types.…

Solar and Stellar Astrophysics · Physics 2021-02-24 Timo Reinhold , Alexander I. Shapiro , Veronika Witzke , Nina-E. Nèmec , Emre Işık , Sami K. Solanki

The space missions MOST, COROT and Kepler are going to provide us with high-precision optical photometry of solar-like stars with time series extending from tens of days to several years. They can be modelled to obtain information on…

Astrophysics · Physics 2008-11-26 A. F. Lanza , A. S. Bonomo , M. Rodono'

A large fraction of cool, low-mass stars exhibit brightness fluctuations that arise from a combination of convective granulation, acoustic oscillations, magnetic activity, and stellar rotation. Much of the short-timescale variability takes…

Solar and Stellar Astrophysics · Physics 2015-06-18 Steven R. Cranmer , Fabienne A. Bastien , Keivan G. Stassun , Steven H. Saar

Stellar rotation periods can be determined by observing brightness variations caused by active magnetic regions transiting visible stellar disk as the star rotates. The successful stellar photometric surveys stemming from the Kepler and…

Solar and Stellar Astrophysics · Physics 2020-10-28 E. M. Amazo-Gomez , A. I. Shapiro , S. K. Solanki , G. Kopp , M. Oshagh , T. Reinhold , A. Reiners

R-mode oscillations in a rotating star produce characteristic signatures in a Fourier amplitude spectrum at frequencies related with the rotation frequency, which can be, in turn, used to obtain the surface rotation rate of the star. Some…

Solar and Stellar Astrophysics · Physics 2022-01-10 Hideyuki Saio , Donald W. Kurtz

Brightness variations due to dark spots on the stellar surface encode information about stellar surface rotation and magnetic activity. In this work, we analyze the Kepler long-cadence data of 26,521 main-sequence stars of spectral types M…

Solar and Stellar Astrophysics · Physics 2019-09-30 A. R. G. Santos , R. A. García , S. Mathur , L. Bugnet , J. L. van Saders , T. S. Metcalfe , G. V. A. Simonian , M. H. Pinsonneault
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