Stellar activity data provide evidence that some activity wave branches propagate polewards rather than equatorwards (the latter being the solar case). This evidence is especially pronounced for the well-observed subgiant HR 1099. For this star, the polar branch seems to coexist with an equatorward branch which propagates through more or less the same latitudinal domain. Stellar dynamo theory allows poleward propagating dynamo waves for certain governing parameters. We discuss the importance of the choice of dynamo governing parameters in fitting the phenomenology of HR 1099.

Ключевые слова: binaries: close – magnetohydrodynamics (MHD) – stars: activity – stars: individual (HR 1099) – stars: magnetic fields