Evolution of the circumstellar disc of alpha Eri
  The Halpha line emission formation region in the circumstellar disc of alpha Eri is: a) extended with a steep outward matter density decline during low H$\alpha$ emission phases; b) less extended with rather constant density distribution during the strong Halpha emission. The long-term variation of the Halpha emission has a 14-15 year cyclic B-Be phase transition. The disc formation time scales agree with the viscous decretion model. The time required for the disc dissipation is longer than expected from the viscous disc model. 
M.M.F. Vinicius (IAGCAUS), N.V. Leister (IAGCAUS), J. Zorec (IAP),   R.S. Levenhagen (IAGCAUS)