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Related papers: Dynamo Saturation in Rapidly Rotating Solar-Type S…

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In the solar convection zone, rotation couples with intensely turbulent convection to build global-scale flows of differential rotation and meridional circulation. Our sun must have rotated more rapidly in its past, as is suggested by…

We examine the generation of a magnetic field in a solar-like star and its effects on the internal distribution of the angular velocity. We suggest that the evolution of a rotating star with magnetic fields leads to an equilibrium value of…

Astrophysics · Physics 2009-11-11 P. Eggenberger , A. Maeder , G. Meynet

The magnetic dynamo mechanism of giant stars remains an open question, which can be explored by investigating their activity-rotation relations with multiple proxies. By using the data from the LAMOST and \emph{GALEX} surveys, we carried…

Solar and Stellar Astrophysics · Physics 2024-11-21 Henggeng Han , Song Wang , Xue Li , Chuanjie Zheng , Jifeng Liu

Many stars exhibit strong magnetic fields, some of which are thought to be of primordial origin and others a sign of magnetic dynamo processes. We briefly review the results of observational studies of solar-type stars seeking to evaluate…

Astrophysics · Physics 2007-05-23 Allan Sacha Brun

The Sun and stars with low magnetic activity levels, become photometrically brighter when their activity increases. Magnetically more active stars display the opposite behaviour and get fainter when their activity increases. We reproduce…

Solar and Stellar Astrophysics · Physics 2015-06-19 A. I. Shapiro , S. K. Solanki , N. A. Krivova , W. K. Schmutz , W. T. Ball , R. Knaack , E. V. Rozanov , Y. C. Unruh

The sunspot solar cycle has been usually explained as the result of a dynamo process operating in the sun. This is a classical problem in Astrophysics that until the present is not fully solved. Here we discuss current problems and…

Astrophysics · Physics 2008-12-08 G. Guerrero , E. M. de Gouveia Dal Pino

Magnetic fields in several astrophysical objects are amplified and maintained by a dynamo mechanism, which is the conversion of the turbulent kinetic energy to magnetic energy. A dynamo that amplifies magnetic fields at scales $<$ the…

Astrophysics of Galaxies · Physics 2021-09-27 Amit Seta , Christoph Federrath

Two fundamental properties of stellar magnetic fields have been determined by observations for solar-like stars with different Rossby numbers (Ro), namely, the magnetic field strength and the magnetic cycle period. The field strength…

Solar and Stellar Astrophysics · Physics 2019-07-24 G. Guerrero , B. Zaire , P. K. Smolarkiewicz , E. M. de Gouveia Dal Pino , A. G. Kosovichev , N. N. Mansour

M dwarfs are the most numerous stars in our Galaxy with masses between approximately 0.5 and 0.1 solar mass. Many of them show surface activity qualitatively similar to our Sun and generate flares, high X-ray fluxes, and large-scale…

Solar and Stellar Astrophysics · Physics 2018-01-29 D. Shulyak A. Reiners , A. Engeln , L. Malo , R. Yadav , J. Morin , O. Kochukhov

We explore a two-dimensional kinematic solar dynamo model in a full sphere, based on the helioseismically determined solar rotation profile and with an $\alpha$ effect concentrated near the solar surface, which captures the…

Astrophysics · Physics 2009-11-10 Piyali Chatterjee , Dibyendu Nandy , Arnab Rai Choudhuri

We investigate differential rotation in rapidly rotating solar-type stars by means of an axisymmetric mean field model that was previously applied to the sun. This allows us to calculate the latitudinal entropy gradient with a rea- sonable…

Solar and Stellar Astrophysics · Physics 2015-05-28 Hideyuki Hotta , Takaaki Yokoyama

The solar cycle appears to be remarkably synchronized with the gravitational torques exerted by the tidally dominant planets Venus, Earth and Jupiter. Recently, a possible synchronization mechanism was proposed that relies on the intrinsic…

Solar and Stellar Astrophysics · Physics 2018-02-14 Frank Stefani , André Giesecke , Norbert Weber , Tom Weier

Observations of sun-like stars rotating faster than our current sun tend to exhibit increased magnetic activity as well as magnetic cycles spanning multiple years. Using global simulations in spherical shells to study the coupling of…

Solar and Stellar Astrophysics · Physics 2015-05-20 Nicholas J. Nelson , Benjamin P. Brown , Matthew K. Browning , Allan Sacha Brun , Mark S. Miesch , Juri Toomre

Models of rapidly rotating massive stars at low metallicities show significantly different evolution and higher metal yields compared to non-rotating stars. We estimate the spin-down time-scale of rapid rotating non-convective stars…

Solar and Stellar Astrophysics · Physics 2015-05-27 Herbert Ho Bun Lau , Adrian T. Potter , Christopher A. Tout

Aims: We study the acceleration of the stellar winds of rapidly rotating low mass stars and the transition between the slow magnetic rotator and fast magnetic rotator regimes. We aim to understand the properties of stellar winds in the fast…

Solar and Stellar Astrophysics · Physics 2017-02-01 C. P. Johnstone

We use two-dimensional axisymmetric magnetohydrodynamic simulations to compute steady-state solutions for solar-like stellar winds from rotating stars with dipolar magnetic fields. Our parameter study includes 50 simulations covering a wide…

Solar and Stellar Astrophysics · Physics 2015-06-05 Sean P. Matt , Keith B. MacGregor , Marc H. Pinsonneault , Thomas P. Greene

The rotation axis of the Sun is misaligned from the mean angular momentum plane of the Solar system by about 6 degrees. This obliquity significantly exceeds the ~1-2 degree distribution of inclinations among the planetary orbits and…

Solar and Stellar Astrophysics · Physics 2019-07-10 Christopher Spalding

The surface rotation rates of young solar-type stars decrease rapidly with age from the end of the pre-main sequence though the early main sequence. This suggests that there is also an important change in the dynamos operating in these…

Solar and Stellar Astrophysics · Physics 2015-06-17 C. P. Folsom , P. Petit , J. Bouvier , J. -F. Donati , J. Morin

We obtain the latitude-time distribution of the averaged tilt angle of solar bipoles. For large bipoles, which are mainly bipolar sunspot groups, the spatially averaged tilt angle is positive in the Northern solar hemisphere and negative in…

Solar and Stellar Astrophysics · Physics 2015-06-15 A. Tlatov , E. Illarionov , D. Sokoloff , V. Pipin

Rotation is a directly-observable stellar property, and drives magnetic field generation and activity through a magnetic dynamo. Main sequence stars with masses below approximately 0.35Msun (mid-to-late M dwarfs) are fully-convective, and…