Hot Post-AGB Stars
| Autor: | G. Gauba, Yoshikazu Nakada, Takahiro Fujii, Mudumba Parthasarathy |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Physics
Reflection nebula Astrophysics::High Energy Astrophysical Phenomena Astronomy Balmer series Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Planetary nebula Protoplanetary nebula symbols.namesake Emission nebula Stellar mass loss symbols Astrophysics::Solar and Stellar Astrophysics Asymptotic giant branch Astrophysics::Earth and Planetary Astrophysics Stellar evolution Astrophysics::Galaxy Astrophysics |
| Zdroj: | Post-AGB Objects as a Phase of Stellar Evolution ISBN: 9789048157587 |
| DOI: | 10.1007/978-94-015-9688-6_4 |
| Popis: | From the study of IRAS sources with far-IR colors similar to planetary nebulae (PNe), several proto-planetary nebulae with hot (OB) post-AGB central stars have been detected. These stars form an evolutionary link between the cooler G,F,A supergiant stars that have evolved off the Asymptotic Giant Branch (AGB) and the hot (OB) central stars of PNe. The optical spectra of these objects show strong Balmer emission lines and in some cases low excitation nebular emission lines such as [NII] and [SII] superposed on the OB stellar continuum. The absence of of [OIII] 5007A line and the presence of low excitation nebular emission lines indicate that photoionisation has just started. The UV(IUE) spectra of some of these objects revealed violet shifted stellar wind P-Cygni profiles of CIV, SiIV and NV, indicating hot and fast stellar wind and post-AGB mass loss. These objects appear to be rapildy evolving into the early stages of PNe similar to that observed in the case of Hen1357 (Stingray Nebula) and SAO85766. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|