Magnetic cycle of LQ Hydrae: observational indications and dynamo model |
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| Authors: | L L Kitchatinov M Jardine J-F Donati |
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| Institution: | School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS;Institute for Solar–Terrestrial Physics, PO Box 4026, Irkutsk, 664033, Russia;Laboratoire d'Astrophysique, Observatoire Midi-Pyrénées, F-31400 Toulouse, France |
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| Abstract: | We present a model for the differential rotation and dynamo activity of the young rapidly rotating K0 dwarf LQ Hya ( P rot=1.6 d). As might be expected from observations of the similar rapid rotator AB Dor, the predicted differential rotation is small (?0.8 per cent) but extremely efficient in generating magnetic fields. The dynamo, which is of a distributed type, produces a globally axisymmetric field with radial and azimuthal components that are of the same magnitude and display a phase-lag in their evolution of about π/2. This is consistent with the long-term Zeeman–Doppler imaging study by Donati. The latitudinal distribution of flux is, however, a little different from that observed and the cycle period of 3.2 yr is somewhat shorter than suggested by the observations. |
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| Keywords: | stars: individual: HD 82558 stars: late-type stars: magnetic fields |
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