Zobrazeno 1 - 10
of 122
pro vyhledávání: '"Käpylä, Petri J."'
Autor:
Käpylä, Petri J.
The canonical undestanding of stellar convection has recently been put under doubt due to helioseismic results and global 3D convection simulations. This "convective conundrum" is manifested by much higher velocity amplitudes in simulations at large
Externí odkaz:
http://arxiv.org/abs/2311.09082
Autor:
Käpylä, Petri J.
(abridged) Context: Rotation is thought to influence the size of convective eddies and the efficiency of convective energy transport in the deep convection zones of stars. Rotationally constrained convection has been invoked to explain the lack of la
Externí odkaz:
http://arxiv.org/abs/2310.12855
We review the state of the art of three dimensional numerical simulations of solar and stellar dynamos. We summarize fundamental constraints of numerical modelling and the techniques to alleviate these restrictions. Brief summary of the relevant obse
Externí odkaz:
http://arxiv.org/abs/2305.16790
Publikováno v:
A&A 678, A9 (2023)
The centrifugal force is often omitted from simulations of stellar convection either for numerical reasons or because it is assumed to be weak compared to the gravitational force. However, it might be an important factor in rapidly rotating stars, su
Externí odkaz:
http://arxiv.org/abs/2305.01312
Autor:
Käpylä, Petri J., Singh, Nishant K.
Turbulent motions enhance the diffusion of large-scale flows and temperature gradients. Such diffusion is often parameterized by coefficients of turbulent viscosity ($\nu_{\rm t}$) and turbulent thermal diffusivity ($\chi_{\rm t}$) that are analogous
Externí odkaz:
http://arxiv.org/abs/2207.10335
Autor:
Käpylä, Petri J.
Publikováno v:
A&A 669, A98 (2023)
(abridged) Context: Late-type stars such as the Sun rotate differentially due to the interaction of turbulent convection and rotation. Aims: The aim of the study is to investigate the effects of the thermal Prandtl number on the transition from anti-
Externí odkaz:
http://arxiv.org/abs/2207.00302
Autor:
Ortiz-Rodríguez, Carolina A., Schleicher, Dominik R. G., Käpylä, Petri J., Navarrete, Felipe H.
M dwarfs are low-mass main-sequence stars, the most numerous type of stars in the solar neighbourhood, which are known to have significant magnetic activity. The aim of this work is to explore the dynamo solutions and magnetic fields of fully convect
Externí odkaz:
http://arxiv.org/abs/2206.14123
Autor:
Navarrete, Felipe H., Schleicher, Dominik R. G., Käpylä, Petri J., Ortiz, Carolina, Banerjee, Robi
Publikováno v:
A&A 667, A164 (2022)
Eclipsing time variations (ETVs) in post-common-envelope binaries (PCEBs) were proposed to be due to the time-varying component of the stellar gravitational quadrupole moment. This is suggested to be produced by changes in the stellar structure due t
Externí odkaz:
http://arxiv.org/abs/2205.03163
Autor:
Käpylä, Petri J.
Magnetohydrodynamic star-in-a-box simulations of convection and dynamos in a solar-like star with different rotation rates are presented. These simulations produce solar-like differential rotation with a fast equator and slow poles, and magnetic acti
Externí odkaz:
http://arxiv.org/abs/2202.04329
Autor:
Käpylä, Petri J.
Publikováno v:
A&A 655, A78 (2021)
(abridged) Context: The ratio of kinematic viscosity to thermal diffusivity, the Prandtl number, is much smaller than unity in stellar convection zones. Aims: To study the statistics of convective flows and energy transport as functions of the Prandt
Externí odkaz:
http://arxiv.org/abs/2105.08453