Evidence for violent ejection of nebulae from massive stars

We report the results of a systematic search for nebulae around Luminous Blue Variable LBVs) and the discovery of a strong correlation between the mass of the nebulae and the luminosity of the central stars. This correlation holds for both the dust and ionized gas masses of the nebulae. The existence of a 'nebular mass-stellar luminosity' relation and the fact that not all LBVs are presently associated with a nebula give evidence against a continuous mass-loss mechanism for the formation of these nebulae. Further, the good agreement found between the observed relation and predictions by Maeder (1989), suggests that all these nebulae may be due to a violent ejection of matter caused by an instability of structural origin.