2 research outputs found
Morphological classification of post-AGB stars
Full text linkWe present a complete study of the morphology of post-Asymptotic Giant Branch
(AGB) stars. Post-AGB is a very short evolutionary phase between the end of the
AGB and the beginning of the Planetary Nebula (PN) stage (between 100 and
10,000 yrs). We have defined the end of the post-AGB phase and the beginning of
the PN phase when the star is hot enough to fully ionize the hydrogen envelope.
Post-AGB stars have a circumstellar shell that is illuminated by the central
stars or partially ionized. However, this circumstellar shell is too small to
be resolved from ground-based observations. Thus, we have used data from the
Hubble Space Telescope (HST) database to resolve these shells. About 150
post-AGB were found in this database. Here we present the preliminary results
on their morphological classification and the correlation with several
parameters such as galactic latitude and IRAS fluxes. Our preliminary results
show that 40% of the sample are stellar-like (S), 33 % bipolar (B), 12 %
multi-polar (M) and 15 % elliptical (E).Comment: proceedings of the conference "Why Galaxies Care About AGB Stars II",
Vienna 2010, eds. Franz Kerschbaum, Thomas Lebzelter and Bob Wing, ASP
Conf.Ser (in press
