Differential rotation in fully convective stars
Under the assumption of thermal wind balance and effective entropy mixing in constant rotation surfaces, the isorotational contours of the solar convective zone may be reproduced with great fidelity. Even at this early stage of development, this helioseismology fit may be used to put a lower bound o...
| Huvudupphovsmän: | , |
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| Materialtyp: | Journal article |
| Språk: | English |
| Publicerad: |
2010
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| _version_ | 1826266038806773760 |
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| author | Balbus, S Weiss, N |
| author_facet | Balbus, S Weiss, N |
| author_sort | Balbus, S |
| collection | OXFORD |
| description | Under the assumption of thermal wind balance and effective entropy mixing in constant rotation surfaces, the isorotational contours of the solar convective zone may be reproduced with great fidelity. Even at this early stage of development, this helioseismology fit may be used to put a lower bound on the mid-latitude radial solar entropy gradient, which is in good accord with standard mixing length theory. In this paper, we generalize this solar calculation to fully convective stars (and potentially planets), retaining the assumptions of thermal wind balance and effective entropy mixing in isorotational surfaces. It is found that each isorotation contour is of the form R2 = A + BΦ(r), where R is the radius from the rotation axis, Φ(r) is the (assumed spherical) gravitational potential, and A and B are constants along the contour. This result is applied to simple models of fully convective stars. Both solar-like surface rotation profiles (angular velocity decreasing toward the poles) as well as 'antisolar' profiles (angular velocity increasing toward the poles) are modelled; the latter bear some suggestive resemblance to numerical simulations. We also perform exploratory studies of zonal surface flows similar to those seen in Jupiter and Saturn. In addition to providing a practical framework for understanding the results of large-scale numerical simulations, our findings may also prove useful in dynamical calculations for which a simple but viable model for the background rotation profile in a convecting fluid is needed. Finally, our work bears directly on an important goal of the CoRoT programme: to elucidate the internal structure of rotating, convecting stars. © 2010 The Authors. Journal compilation © 2010 RAS. |
| first_indexed | 2024-03-06T20:32:52Z |
| format | Journal article |
| id | oxford-uuid:31a60dd1-76b6-4a17-81cb-f8c49430aa43 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:32:52Z |
| publishDate | 2010 |
| record_format | dspace |
| spelling | oxford-uuid:31a60dd1-76b6-4a17-81cb-f8c49430aa432022-03-26T13:09:16ZDifferential rotation in fully convective starsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:31a60dd1-76b6-4a17-81cb-f8c49430aa43EnglishSymplectic Elements at Oxford2010Balbus, SWeiss, NUnder the assumption of thermal wind balance and effective entropy mixing in constant rotation surfaces, the isorotational contours of the solar convective zone may be reproduced with great fidelity. Even at this early stage of development, this helioseismology fit may be used to put a lower bound on the mid-latitude radial solar entropy gradient, which is in good accord with standard mixing length theory. In this paper, we generalize this solar calculation to fully convective stars (and potentially planets), retaining the assumptions of thermal wind balance and effective entropy mixing in isorotational surfaces. It is found that each isorotation contour is of the form R2 = A + BΦ(r), where R is the radius from the rotation axis, Φ(r) is the (assumed spherical) gravitational potential, and A and B are constants along the contour. This result is applied to simple models of fully convective stars. Both solar-like surface rotation profiles (angular velocity decreasing toward the poles) as well as 'antisolar' profiles (angular velocity increasing toward the poles) are modelled; the latter bear some suggestive resemblance to numerical simulations. We also perform exploratory studies of zonal surface flows similar to those seen in Jupiter and Saturn. In addition to providing a practical framework for understanding the results of large-scale numerical simulations, our findings may also prove useful in dynamical calculations for which a simple but viable model for the background rotation profile in a convecting fluid is needed. Finally, our work bears directly on an important goal of the CoRoT programme: to elucidate the internal structure of rotating, convecting stars. © 2010 The Authors. Journal compilation © 2010 RAS. |
| spellingShingle | Balbus, S Weiss, N Differential rotation in fully convective stars |
| title | Differential rotation in fully convective stars |
| title_full | Differential rotation in fully convective stars |
| title_fullStr | Differential rotation in fully convective stars |
| title_full_unstemmed | Differential rotation in fully convective stars |
| title_short | Differential rotation in fully convective stars |
| title_sort | differential rotation in fully convective stars |
| work_keys_str_mv | AT balbuss differentialrotationinfullyconvectivestars AT weissn differentialrotationinfullyconvectivestars |