Evolution of the circumstellar disc of alpha Eri

M. M. F. Vinicius, N. V. Leister, J. Zorec, R. S. Levenhagen

Published 2006-01-04Version 1

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.