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We use Doppler imaging techniques to determine the dependence of starspot rotation rates on latitude in an homogeneous sample of young, rapidly-rotating solar analogues. A solar-like differential rotation law is used, where the rotation…

Astrophysics · Physics 2009-11-10 J. R. Barnes , A. Collier Cameron , J. -F. Donati , D. J. James , S. C. Marsden , P. Petit

We present an analytic model of the lightcurve variation for stars with non-evolving starspots on a differentially rotating surface. The Fourier coefficients of the harmonics of the rotation period are expressed in terms of the latitude of…

Solar and Stellar Astrophysics · Physics 2022-08-17 Yasushi Suto , Shin Sasaki , Yuta Nakagawa , Othman Benomar

Starspots and their movements on stellar surfaces enable investigating the mechanisms of stellar magnetic activity. Information on the spot distribution and differential rotation provide important constraints for the behaviour of stellar…

Solar and Stellar Astrophysics · Physics 2026-03-25 Mikko Tuomi , András Haris , Thomas Hackman

Surface differential rotation (SDR) plays a key role in dynamo models. SDR estimates are therefore essential for constraining theoretical models. We measure a lower limit to SDR in a sample of solar-like stars belonging to young…

Solar and Stellar Astrophysics · Physics 2016-06-15 E. Distefano , A. C. Lanzafame , A. F. Lanza , S. Messina , F. Spada

Rapid rotation enhances the dynamo operating in stars, and thus also introducessignificantly stronger magnetic activity than is seen in slower rotators. Many young cool stars still have the rapid, primordial rotation rates induced by the…

Solar and Stellar Astrophysics · Physics 2015-06-03 H. Korhonen

The high-precision photometry from the CoRoT and Kepler satellites has led to measurements of surface rotation periods for tens of thousands of stars. Our main goal is to derive ages of thousands of field stars using consistent rotation…

Solar and Stellar Astrophysics · Physics 2015-10-28 Timo Reinhold , Laurent Gizon

In this work the latitude dependent stellar spot rotation is investigated based on dynamo models. The maps of the magnetic pressure at the surface from the dynamo calculations are treated similarly to the temperature maps obtained using…

Solar and Stellar Astrophysics · Physics 2015-05-28 H. Korhonen , D. Elstner

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

Context. There exist few variability studies of stars in the region in the Hertzsprung-Russell diagram between the A and B-star pulsational instability strips. With the aid of the high precision continuous measurements of the CoRoT space…

Solar and Stellar Astrophysics · Physics 2015-05-30 P. Degroote , B. Acke , R. Samadi , C. Aerts , D. W. Kurtz , A. Noels , A. Miglio , J. Montalban , S. Bloemen , A. Baglin , F. Baudin , C. Catala , E. Michel , M. Auvergne

We report the discovery of a new relationship between a simple morphological characteristic of light curves produced by starspots and stellar rotation periods. The characteristic we examine is whether the light curve exhibits one dip or two…

Solar and Stellar Astrophysics · Physics 2018-08-29 Gibor Basri , Hieu T. Nguyen

The NASA Kepler mission is providing an unprecedented set of asteroseismic data. In particular, short-cadence lightcurves (~60s samplings), allow us to study solar-like stars covering a wide range of masses, spectral types and evolutionary…

The light curves of old G-dwarfs obtained in the visible and near-infrared wavelength ranges are highly irregular. This significantly complicates the detectability of the rotation periods of stars similar to the Sun in large photometric…

Solar and Stellar Astrophysics · Physics 2025-02-26 Valeriy Vasilyev , Timo Reinhold , Alexander I. Shapiro , Theodosios Chatzistergos , Natalie Krivova , Sami K. Solanki

Stellar rotation plays a key role in stellar activity. The rotation period could be detected through light curve variations caused by starspots. Kepler provides two types of light curves, one is the Pre-search Data Conditioning (PDC) light…

Solar and Stellar Astrophysics · Physics 2019-10-02 Kaiming Cui , Jifeng Liu , Shuhong Yang , Qing Gao , Huiqin Yang , Roberto Soria , Lin He , Song Wang , Yu Bai , Fan Yang

Understanding differential rotation of Sun-like stars is of great importance for insight into the angular momentum transport in these stars. One means of gaining such information is that of asteroseismology. By a forward modeling approach…

Solar and Stellar Astrophysics · Physics 2016-02-22 Mikkel N. Lund , Mark S. Miesch , Jørgen Christensen-Dalsgaard

We first reported evidence for differential rotation of Kappa1 Ceti in Paper I. In this paper we demonstrate that the differential rotation pattern closely matches that for the Sun. This result is based on additional MOST (Microvariability…

About 10% of upper main sequence stars are characterised by the presence of chemical peculiarities, often found together with a structured magnetic field. The atmospheres of most of those chemically peculiar stars present surface spots,…

Solar and Stellar Astrophysics · Physics 2015-06-03 K. T. Wraight , L. Fossati , M. Netopil , E. Paunzen , M. Rode-Paunzen , D. Bewsher , A. J. Norton , G. J. White

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

Rotational light modulation in Kepler photometry of K - A stars is used to estimate the absolute rotational shear. The rotation frequency spread in 2562 carefully selected stars with known rotation periods is measured using time-frequency…

Solar and Stellar Astrophysics · Physics 2016-07-27 Luis A. Balona , Oyirwoth P. Abedigamba

We present a study on the determination of rotation periods (P) of solar-like stars from the photometric irregular time-sampling of the ESA Gaia mission, currently scheduled for launch in 2013, taking into account its dependence on ecliptic…

Solar and Stellar Astrophysics · Physics 2015-06-04 E. Distefano , A. C. Lanzafame , A. F. Lanza , S. Messina , A. J. Korn , K. Eriksson , J. Cuypers

V889 Herculis is one of the brightest single early-G type stars, a young Sun, that is rotating fast enough (P_rot =1.337 days) for mapping its surface by Doppler Imaging. The 10 FOCES spectra collected between 13-16 Aug 2006 at Calar Alto…

Solar and Stellar Astrophysics · Physics 2015-05-20 Zsolt Kovari , Antonio Frasca , Katia Biazzo , Krisztian Vida , Ettore Marilli , Omur Cakirli