A review of some of the properties of planetary nebulae viewed as post-asymptotic giant branch objects is given. Some recent results are listed on the HR Diagram for central stars, nebular morphology and giant halos, and CNO abundances in nebulae. A distance-independent comparison of the HR Diagrams for central stars and AGB stars in the LMC is made. It is concluded that high mass-loss rates terminate the AGB evolution at luminosities lower than usually predicted. The great majority of Galactic PNs are post-AGB objects, but attention is drawn to two important exceptions. New results from the analyses of PN giant halos are given. The CNO abundances of PNs and red giant envelopes are compared.
From Miras to Planetary Nebulae: Which Path for Stellar Evolution?
- Pub Date:
- Asymptotic Giant Branch Stars;
- Planetary Nebulae;
- Stellar Evolution;
- Stellar Mass Ejection;
- Hertzsprung-Russell Diagram;
- Stellar Envelopes;