Abell 48 - a rare WN-type central star of a planetary nebula
| Autor: | T. E. Pickering, T. O. Husser, Vasilii V. Gvaramadze, Amanda A. S. Gulbis, Encarni Romero-Colmenero, Eric J. Hooper, S. B. Potter, Marsha J. Wolf, D. A. H. Buckley, P. Kotze, Christian Hettlage, N. S. Loaring, Petri Väisänen, Kenneth H. Nordsieck, Helge Todt, L. Crause, A. Y. Kniazev, T. B. Williams, S. Crawford, Wolf-Rainer Hamann, Donal O'Donoghue |
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| Rok vydání: | 2013 |
| Předmět: |
Physics
Hydrogen 010308 nuclear & particles physics chemistry.chemical_element Astronomy FOS: Physical sciences Astronomy and Astrophysics Astrophysics Star (graph theory) 01 natural sciences Planetary nebula Spectral line Atmospheric composition Stars Astrophysics - Solar and Stellar Astrophysics chemistry 13. Climate action Space and Planetary Science 0103 physical sciences Spectral analysis 010303 astronomy & astrophysics Helium Solar and Stellar Astrophysics (astro-ph.SR) |
| DOI: | 10.48550/arxiv.1301.1944 |
| Popis: | A considerable fraction of the central stars of planetary nebulae (CSPNe) are hydrogen-deficient. Almost all of these H-deficient central stars (CSs) display spectra with strong carbon and helium lines. Most of them exhibit emission line spectra resembling those of massive WC stars. Therefore these stars are classed as CSPNe of spectral type [WC]. Recently, quantitative spectral analysis of two emission-line CSs, PB 8 and IC 4663, revealed that these stars do not belong to the [WC] class. Instead PB 8 has been classified as [WN/WC] type and IC 4663 as [WN] type. In this work we report the spectroscopic identification of another rare [WN] star, the CS of Abell 48. We performed a spectral analysis of Abell 48 with the Potsdam Wolf-Rayet (PoWR) models for expanding atmospheres. We find that the expanding atmosphere of Abell 48 is mainly composed of helium (85 per cent by mass), hydrogen (10 per cent), and nitrogen (5 per cent). The residual hydrogen and the enhanced nitrogen abundance make this object different from the other [WN] star IC 4663. We discuss the possible origin of this atmospheric composition. Comment: 12 pages, 10 figures, accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
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