Antisolar differential rotation of slowly rotating cool stars
- Rotating stellar convection transports angular momentum towards the equator, generating the characteristic equatorial acceleration of the solar rotation while the radial flux of angular momentum is always inwards. New numerical box simulations for the meridional cross-correlation < u(theta)u(phi)>, however, reveal the angular momentum transport towards the poles for slow rotation and towards the equator for fast rotation. The explanation is that for slow rotation a negative radial gradient of the angular velocity always appears, which in combination with a so-far neglected rotation-induced off-diagonal eddy viscosity term nu(perpendicular to) provides "antisolar rotation" laws with a decelerated equator Similarly, the simulations provided positive values for the rotation-induced correlation < u(r)u(theta)>, which is relevant for the resulting latitudinal temperature profiles (cool or warm poles) for slow rotation and negative values for fast rotation. Observations of the differential rotation of slowly rotating stars will thereforeRotating stellar convection transports angular momentum towards the equator, generating the characteristic equatorial acceleration of the solar rotation while the radial flux of angular momentum is always inwards. New numerical box simulations for the meridional cross-correlation < u(theta)u(phi)>, however, reveal the angular momentum transport towards the poles for slow rotation and towards the equator for fast rotation. The explanation is that for slow rotation a negative radial gradient of the angular velocity always appears, which in combination with a so-far neglected rotation-induced off-diagonal eddy viscosity term nu(perpendicular to) provides "antisolar rotation" laws with a decelerated equator Similarly, the simulations provided positive values for the rotation-induced correlation < u(r)u(theta)>, which is relevant for the resulting latitudinal temperature profiles (cool or warm poles) for slow rotation and negative values for fast rotation. Observations of the differential rotation of slowly rotating stars will therefore lead to a better understanding of the actual stress-strain relation, the heat transport, and the underlying model of the rotating convection.…
Verfasserangaben: | Günther RüdigerORCiDGND, Manfred KükerORCiD, P. J. Kapyla, Klaus G. StrassmeierORCiDGND |
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DOI: | https://doi.org/10.1051/0004-6361/201935280 |
ISSN: | 1432-0746 |
Titel des übergeordneten Werks (Englisch): | Astronomy and astrophysics : an international weekly journal |
Verlag: | EDP Sciences |
Verlagsort: | Les Ulis |
Publikationstyp: | Wissenschaftlicher Artikel |
Sprache: | Englisch |
Datum der Erstveröffentlichung: | 23.07.2019 |
Erscheinungsjahr: | 2019 |
Datum der Freischaltung: | 04.11.2020 |
Freies Schlagwort / Tag: | convection; stars: rotation; stars: solar-type; turbulence |
Band: | 630 |
Seitenanzahl: | 9 |
Fördernde Institution: | Deutsche Forschungsgemeinschaft Heisenberg programme [KA 4825/1-1]; Academy of Finland ReSoLVE Centre of Excellence [307411] |
Organisationseinheiten: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
DDC-Klassifikation: | 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik |
Peer Review: | Referiert |
Publikationsweg: | Open Access |
Open Access / Bronze Open-Access |