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Related papers: Differential Rotation in F Stars

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Context. While rotation has a major impact on stellar structure and evolution, its effects are not well understood. Thanks to high- quality and long timebase photometric observations obtained with recent space missions, we are now able to…

We have investigated the effects of uniform rotation and a specific model for differential rotation on the pulsation frequencies of 10 \Msun\ stellar models. Uniform rotation decreases the frequencies for all modes. Differential rotation…

Astrophysics · Physics 2011-02-11 C. C. Lovekin , R. G. Deupree , M. J. Clement

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 propose a method for measuring the projected rotational velocity $v sin i$ with high-precision even in spectra with blended lines. Though not automatic, our method is designed to be applied systematically to large numbers of objects…

Solar and Stellar Astrophysics · Physics 2013-04-22 C. G. Díaz , J. F. González , H. Levato , M. Grosso

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

To date, asteroseismology has provided core to surface differential rotation measurements in eight main-sequence stars. These stars, ranging in mass from $\sim$1.5-9$M_\odot$, show rotation profiles ranging from uniform to counter-rotation.…

Solar and Stellar Astrophysics · Physics 2015-12-23 T. M. Rogers

Differential rotation is a key driver of magnetic activity and dynamo processes in the Sun and other stars, especially as the rate differs across the solar layers, but also in active regions. We aim to accurately quantify the velocity at…

Stellar rotation is crucial for studying stellar evolution since it provides information about age, angular momentum transfer, and magnetic fields of stars. In the case of the Sun, due to its proximity, detailed observation of sunspots at…

Solar and Stellar Astrophysics · Physics 2023-09-20 Araújo , Valio

Context: Mode identification has remained a major obstacle in the interpretation of pulsation spectra in rapidly rotating stars. Aims: We would like to test mode identification methods and seismic diagnostics in rapidly rotating stars,…

Solar and Stellar Astrophysics · Physics 2017-05-24 D. R. Reese , F. Lignières , J. Ballot , M. -A. Dupret , C. Barban , C. van 't Veer-Menneret , K. B. MacGregor

On the Sun, the rotation periods of individual sunspots not only trace the latitude dependence of the surface rotation rate, but also provide clues as to the amount of subsurface fluid shear. In this paper we present the first measurements…

Astrophysics · Physics 2009-11-07 A. Collier Cameron , J. -F. Donati , M. Semel

Differential rotation plays a crucial role in the alpha-omega dynamo, and thus also in creation of magnetic fields in stars with convective outer envelopes. Still, measuring the radial differential rotation on stars is impossible with the…

Astrophysics · Physics 2009-11-13 H. Korhonen , D. Elstner

The Fourier Transform method is a popular tool to derive the rotational velocities of stars from their spectral line profiles. However, its domain of validity does not include line-profile variables with time-dependent profiles. We…

Solar and Stellar Astrophysics · Physics 2014-10-01 C. Aerts , S. Simon-Diaz , P. J. Groot , P. Degroote

Rapidly and differentially rotating compact stars are believed to be formed in binary neutron star merger events, according to both numerical simulations and the multi-messenger observation of GW170817. The lifetime and evolution of such a…

High Energy Astrophysical Phenomena · Physics 2019-08-21 Enping Zhou , Antonios Tsokaros , Koji Uryu , Renxin Xu , Masaru Shibata

Context: Rotation plays a key role in the life cycles of stars with masses above 8 Msun. Hence, accurate knowledge of the rotation rates of such massive stars is critical for understanding their properties and for constraining models of…

Solar and Stellar Astrophysics · Physics 2015-06-17 J. O. Sundqvist , S. Simon-Diaz , J. Puls , N. Markova

We present a comprehensive study that applies the Fourier transform to a sample of O and early B-type stars (either dwarfs, giants, or supergiants) to determine their projected rotational velocities, compare with previous values obtained…

Astrophysics · Physics 2016-08-14 S. Simón-Díaz , A. Herrero

Detecting and understanding rotation in stellar interiors is nowadays one of the unsolved problems in stellar physics. Asteroseismology has been able to provide insights on rotation for the Sun, solar-like stars, and compact objects like…

Solar and Stellar Astrophysics · Physics 2021-06-24 A. Ramón-Ballesta , A. García Hernández , J. C. Suárez , J. R. Rodón , J. Pascual-Granado , R. Garrido

The solar photosphere, chromosphere and corona are known to rotate differentially as a function of latitude. To date, it is unclear if the solar transition region also rotates differentially. In this paper, we investigate differential…

Solar and Stellar Astrophysics · Physics 2021-07-21 Jaidev Sharma , Brajesh Kumar , Anil K Malik , Hari Om Vats

We take advantage of interferometric measurements of Achernar to inquire on its internal rotational law. The reinterpretation of interferome-tric data and the use of fundamental parameters corrected for gravitational darkening effects and…

Astrophysics · Physics 2007-05-23 Juan Zorec , Armando Domiciano De Souza , Yves Fremat , Farok Vakli

We assume that stars may undergo surface differential rotation to study its impact on the interpretation of $V\!\sin i$ and on the observed distribution $\Phi(u)$ of ratios of true rotational velocities $u=V/V_\rm c$ ($V_\rm c$ is the…

Solar and Stellar Astrophysics · Physics 2017-06-21 J. Zorec , Y. Frémat , A. Domiciano de Souza , F. Royer , L. Cidale , A. -M. Hubert , T. Semaan , C. Martayan , Y. R. Cochetti , M. L. Arias , Y. Aidelman , P. Stee

We present rotation periods for thousands of active stars in the Kepler field derived from Q3 data. In most cases a second period close to the rotation period was detected, which we interpreted as surface differential rotation (DR). Active…

Solar and Stellar Astrophysics · Physics 2015-06-16 Timo Reinhold , Ansgar Reiners , Gibor Basri