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Two models of the circumstellar disc around supergiant B[e] stars arediscussed: an equatorial wind model produced by wind bi-stability, and aKeplerian viscous disc model. Both models are successful in providing a sitefor dust formation once they have cooled sufficiently. However, theoptical--infra-red continuum is calculated and it is found that both modelshave significant trouble in accounting for observations. In particular theoptical--near-IR emission is accounted for, but the dust emission isunderestimated by at least an order of magnitude. Variations in the structureof the models (the temperature variation with radius, the density structure andthe dust opacity) are investigated to assess how (in)appropriate the standardmodels are for supergiant B[e] star discs. Changing the temperature structure,and making simple dust opacity changes within the disc has little effect on theresultant continuum emission. By altering the density structure of the discs,the continuum may be accounted for by both models: the equatorial wind modelrequires a very flat density profile which is impossible to explain with anyaccelerating wind, and the viscous disc model's density structure is requiredto fall off less steeply with radius than would have been expected, althoughthis may be explained from consideration of viscous processes in the disc. Itis recognised that both theoretical interpretations have difficulties andunsolved problems.Comment: 9 pages, 6 figures, accepted by Astronomy and Astrophysic

On the optical–infra-red continuum emission from equatorial discs of supergiant B[e] stars