Resumé
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Symposium - International astronomical union |
| Vol/bind | 219 |
| Sider (fra-til) | 656-660 |
| ISSN | 0074-1809 |
| Status | Udgivet - 2004 |
| Udgivet eksternt | Ja |
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A magnetic betelgeuse? Numerical simulations of non-linear dynamo action : 219th IAU Symposium on Stars as Suns - Activity, Evolution, and Planets, JUL 21-25, 2003 Sydney, AUSTRALIA. / Dorch, S. B. F.
I: Symposium - International astronomical union, Bind 219, 2004, s. 656-660.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning
TY - JOUR
T1 - A magnetic betelgeuse? Numerical simulations of non-linear dynamo action
T2 - 219th IAU Symposium on Stars as Suns - Activity, Evolution, and Planets, JUL 21-25, 2003 Sydney, AUSTRALIA
AU - Dorch, S. B. F.
PY - 2004
Y1 - 2004
N2 - Betelgeuse is an example of a cool super-giant displaying brightness fluctuations and irregular surface structures. Simulations by Freytag et al. (2002) of the convective envelope of the star have shown that the fluctuations in the star's luminosity may be caused by giant cell convection. A related question regarding the nature of Betelgeuse and supergiants in general is whether these stars may be magnetically active. If so, that may in turn also contribute to their variability. By performing detailed numerical simulations, I find that both linear kinematic and non-linear dynamo action are possible and that the non-linear magnetic field saturates at a value somewhat below equipartition: in the linear regime there are two modes of dynamo action.
AB - Betelgeuse is an example of a cool super-giant displaying brightness fluctuations and irregular surface structures. Simulations by Freytag et al. (2002) of the convective envelope of the star have shown that the fluctuations in the star's luminosity may be caused by giant cell convection. A related question regarding the nature of Betelgeuse and supergiants in general is whether these stars may be magnetically active. If so, that may in turn also contribute to their variability. By performing detailed numerical simulations, I find that both linear kinematic and non-linear dynamo action are possible and that the non-linear magnetic field saturates at a value somewhat below equipartition: in the linear regime there are two modes of dynamo action.
M3 - Journal article
VL - 219
SP - 656
EP - 660
JO - Proceedings of the International Astronomical Union
JF - Proceedings of the International Astronomical Union
SN - 1743-9213
ER -