Spectroscopy of the post-AGB star HD 101584 (IRAS 11385-5517)

From an analysis of the spectrum (4000 Angstrom to 8800 Angstrom) of HD 101584 it is found that most of the neutral and single ionized metallic lines are in emission. The forbidden emission lines of [OI] 6300 Angstrom and 6363 Angstrom and [CI] 8727 Angstrom are detected, which indicate the presence of a very low excitation nebula. The H alpha, FeII 6383 Angstrom, Nd D-1, D-2 lines and the CaII IR triplet lines show P-Cygni profiles indicating a mass outflow. The H alpha line shows many velocity components in the profile. The FeII 6383 Angstrom also has almost the same line profile as the H alpha line indicating that they are formed in the same region. From the spectrum synthesis analysis we find the atmospheric parameters to be T-eff = 8500 K, log g = 1.5, V-turb = 13 km s(-1) and [Fe/H] = 0.0. From an analysis of the absorption lines the photospheric abundances of some of the elements are derived. Carbon and nitrogen are found to be overabundant. From the analysis of Fe emission lines we derived T-exi = 6100 K +/- 200 for the emission line region.