EDP Sciences
Free Access
Volume 368, Number 1, March II 2001
Page(s) 250 - 266
Section Stellar atmospheres
DOI https://doi.org/10.1051/0004-6361:20000572

A&A 368, 250-266 (2001)
DOI: 10.1051/0004-6361:20000572

Atmospheric abundances in post-AGB candidates of intermediate temperature

A. Arellano Ferro1, Sunetra Giridhar2 and P. Mathias3

1  Instituto de Astronomía, Universidad Nacional Autónoma de México, Apdo. Postal 70-264, México D.F., CP 04510, México
2  Indian Institute of Astrophysics, Bangalore 560034, India
    e-mail: giridhar@iiap.ernet.in
3  Observatoire de la Côte d'Azur, Département Fresnel, UMR 6528, BP 4229, 06304 Nice Cedex 04, France
    e-mail: mathias@obs-nice.fr

(Received 23 August 2000 / Accepted 19 December 2000)

Detailed atmospheric abundances have been calculated for a sample of A-G supergiant stars with IR fluxes and/or high galactic latitudes. HD 172481 and HD 158616 show clear indications of being post-AGB stars that have experienced third dredge-up. HD 158616 is carbon-rich while the abundance pattern of HD 172481 and its large Li enhancement gives support to the hot bottom burning scenario that explains paucity of carbon-rich stars among AGB stars. HD 172324 is very likely a hot post-AGB star that shows a strong carbon deficiency. HD 725, HD 218753 and HD 331319 also appear to be evolved objects between the red giant and the AGB. HD 9167, HD 173638 with a few exceptions, reflect solar abundances and no signs of post red giant evolution. They are most likely young massive disk supergiants. Further analysis of proto-Planetary Nebula HDE 341617 reveals that He lines show signs of velocity stratification. The emission lines have weakened considerably since 1993. The envelope expands at 19 km s-1 relative to the star. Atmospheric abundances, evolutionary tracks and isochrones are used to estimate masses and ages of all stars in the sample.

Key words: stars: post-AGB -- stars: chemically peculiar -- stars: evolution

Offprint request: A. Arellano Ferro armando@astroscu.unam.mx

SIMBAD Objects

© ESO 2001

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.