Bibcode
                                    
                            Crivellari, L.; Praderie, F.
    Referencia bibliográfica
                                    Astronomy and Astrophysics, vol. 107, no. 1, Mar. 1982, p. 75-87. Research supported by the Consiglio Nazionale delle Ricerche.
Fecha de publicación:
    
                        3
            
                        1982
            
  Revista
                                    
                            Número de citas
                                    25
                            Número de citas referidas
                                    22
                            Descripción
                                    Observations of the 1400-1800 A region in late A type stars are
presented, which were obtained using the IUE satellite at low and high
resolution. The calibrated energy distribution is derived and presents a
large variation with wavelength in the spectral range due to Si I
photoionization discontinuities. Emission lines formed in the transition
region do not appear, although upper limits on the emission in these
lines are established. A schematic model is proposed for the outer
layers in A type stars, which suggests that the chromosphere in solar
type stars is likely absent in A stars, while the NLTE photosphere could
be immediately connected to the transition region, joining the upper
photosphere to the corona. In addition, the amount of matter in the
transition zone is found to be small.