Astron. Astrophys. Suppl. Ser. 137, 505-519

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

T. Sivarani¹ - M. Parthasarathy¹ - P. García-Lario² - A. Manchado³ - S.R. Pottasch⁴

Send offprint request: T. Sivarani

Correspondence to: sivarani@iiap.ernet.in

1 - Indian Institute of Astrophysics, Bangalore 560 034, India
2 - ISO Data Centre, Astrophysics Division, Space Science Department of ESA, Villafranca del Castillo, Apartado de Correos 50727, E-28080 Madrid, Spain
3 - Instituto de Astrofisica de Canarias, E-38200 La Laguna, Tenerife, Spain
4 - Kapteyn Astronomical Institute, Postbus 800, NL-9700 AV Groningen, The Netherlands

Received October 22, 1998; accepted May 12, 1999

Abstract:

From an analysis of the spectrum (4000 Å to 8800 Å) 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 Å and 6363 Å and [CI] 8727 Å are detected, which indicate the presence of a very low excitation nebula. The H$\alpha$, FeII 6383 Å, NaI D₁, D₂ 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 Å 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 $T_{\rm eff}=8500$ K, log g=1.5, $V_{\rm turb}=13$ 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 $T_{\rm exi}=6100$ K $\pm$ 200 for the emission line region.

Key words: stars: abundances-stars: evolution-stars: post-AGB-stars: circumstellar matter-stars: individual: HD 101584