Bibcode
Manchado, A.; García-Hernández, D. A.; Villaver, E.; Guironnet de Massas, J.
Referencia bibliográfica
Why Galaxies Care about AGB Stars II: Shining Examples and Common Inhabitants. Proceedings of a conference held at University Campus, Viena, Austria, 16-20 August 2010. Edited by F. Kerschbaum, T. Lebzelter, and R.F. Wing. San Francisco: Astronomical Society of the Pacific, 2011., p.161
Fecha de publicación:
9
2011
Número de citas
9
Número de citas referidas
7
Descripción
We present a complete study of the morphology of post-Asymptotic Giant
Branch (post-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 as when the star
becomes hot enough to fully ionize the hydrogen envelope. Post-AGB
stars have a circumstellar shell that is illuminated by the central
star or partially ionized. However, this circumstellar shell is too
small to be resolved by ground-based observations. Thus, we have used
data from the Hubble Space Telescope (HST) database to resolve these
shells. About 150 post-AGB stars 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 flux. Our preliminary results show that 40 % of the sample are
stellar-like (S), 33 % bipolar (B), 12 % multi-polar (M), and 15 %
elliptical (E).