High-latitude supergiant V5112 Sgr: enrichment of the envelope with heavy s-process metals

Abstract

High-resolution (R=60000) echelle spectroscopy of the post-AGB supergiant V5112 Sgr performed in 1996-2012 with the 6-m telescope BTA has revealed peculiarities of the star optical spectrum and has allowed the variability of the velocity field in the stellar atmosphere and envelope to be studied in detail. An asymmetry and splitting of strong absorption lines with a low lower-level excitation potential have been detected for the first time. The effect is maximal in BaII lines whose profile is split into three components. The profile shape and positions of the split lines change with time. The blue components of the split absorption lines are shown to be formed in a structured circumstellar envelope, suggesting an efficient dredge-up of the heavy metals produced during the preceding evolution of this star into the envelope. The envelope expansion velocities have been estimated to be 20 and 30 km/s. The mean radial velocity from diffuse bands in the spectrum of V5112 Sgr coincides with that from the short-wavelength shell component of the NaI D lines, which leads to the conclusion about their formation in the circumstellar envelope. Analysis of the set of radial velocities Vr based on symmetric absorption lines has confirmed the presence of pulsations in the stellar atmosphere with an amplitude 8 km/s.

16 pages, 5 figures, 3 tables

References in corpus (10)

• A Catalog of Diffuse Interstellar Bands in the Spectrum of HD 204827
• Preplanetary Nebulae: An HST Imaging Survey and a New Morphological Classification System
• Echelle long-slit optical spectroscopy of evolved stars
• A search for diffuse bands in the circumstellar envelopes of post-AGB stars
• V2324Cyg - an F-type star with fast wind
• Kinematic structure of the atmosphere and envelope of the post-AGB star HD56126
• Peculiarities and variations in the optical spectrum of the post-AGB star V448Lac=IRAS22223+4327
• The evolutionary status of the semiregular variable QYSge
• Detection of heavy-metal lines in the spectrum of the circumstellar envelope of a post-AGB star
• IR-source IRAS20508+2011: spectral variability of the central star

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