Distances to Planetary Nebulae: A Key to Galactic Structure and Evolution

Corradi, R.; Mampaso, A.; Navarro, S.
Bibliographical reference

"IX Latin American Regional IAU Meeting, "Focal Points in Latin American Astronomy", held in Tonantzintla, Mexico, Nov 9-13, 1998, Eds: Aguilar, A.; Carraminana, A.; to be printed in Revista Mexicana de Astronomia y Astrofisica Serie de Conferencias."

Advertised on:
11
1998
Number of authors
3
IAC number of authors
3
Citations
0
Refereed citations
0
Description
The knowledge of accurate distances to Planetary Nebulae (PNe) is necesary in order to improve the determination of some physical quantities such as the nebular radius and mass. The nebular mass is a critical parameter to determine the amount of mass that is returned to the interstellar medium by the PN. This mass return can influence the evolution of the whole Galaxy. This is a project that obtained 50% of the International Time (ITP) for 1997 in the Canarias International Observatories. The principal goal of the project is to determine accurate distances (uncertain < 30%) to about 50 PNe by means of the extinction-distance method. The extinction-distance relation will be determined in the direction of each of the PNe, using the spectra of near 3000 field stars (about 60 in each PN field). The determination of the spectral type will be made upon the Artificial Neural Networw (ANN) techniques, which have proved to be a powerful method of stellar classification. (Gulati et al. 1994, Singh et al. 1998, Viera & Ponz 1995). In this contribution we will describe the advance in the observation and analysis work that was made until now and the first results obtained recently.