Trace elements and evolution of PG 1159 stars

• Applicant: Dr. Thomas Rauch
• Subject Area: Astrophysics and Astronomy
• Term: from 2002 to 2003
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5382792

Modern spectral analysis of hot helium-rich post-AGB stars has improved our picture of their evolution: They are likely so-called "born-again post-AGB" stars. However, the results of our analyses had been inconsistent with predictions of standard evolutionary calculations: These had shown the observed abundance pattern deep inside the atmosphere covered by thick helium and hydrogen shells and thus, far from being observable. Newly developed evolutionary models can predict now these abundances. The photospheric hydrogen, nitrogen and neon content are important indicators to test these calculations and to give constraints for the further evolution of these stars.

• DFG Programme: Research Grants