The shape of eta Carinae and LBV nebulae

Stellar winds emitted by rotating massive stars may show two main component s: firstly bipolar lobes with low density and fast wind, produced by the hi gher T-eff and gravity at the poles ("geff-effect"); secondly, an equatoria l disc with a slow dense wind, produced by the stronger opacities at the eq uator ("k-effect"). To see the possible role of this anisotropic wind on th e shape of LBV nebulae, we calculate the distribution of the ejected matter in 2 simplified cases: 1) A brief shell ejection. We find that prolate and peanut-shaped hollow nebulae naturally form due to the g(eff)-effect in ro tating stars. 2) A constant wind for a long time. This produces prolate fil led nebulae, with a possible strong disc when a bi-stability limit is cross ed in the equatorial region. Thus, many features of the eta Carinae and LBV nebulae are accounted for by the anisotropic ejection from rotating stars.