TY  - JOUR
A1  - Todt, Helge Tobias
A1  - Kniazev, A. Y.
A1  - Gvaramadze, V. V.
A1  - Hamann, Wolf-Rainer
A1  - Buckley, D.
A1  - Crause, L.
A1  - Crawford, S. M.
A1  - Gulbis, A. A. S.
A1  - Hettlage, C.
A1  - Hooper, E.
A1  - Husser, T. -O.
A1  - Kotze, P.
A1  - Loaring, N.
A1  - Nordsieck, K. H.
A1  - O'Donoghue, D.
A1  - Pickering, T.
A1  - Potter, S.
A1  - Romero-Colmenero, E.
A1  - Vaisanen, P.
A1  - Williams, T.
A1  - Wolf, M.
T1  - Abell 48-a rare WN-type central star of a planetary nebula
T2  - Monthly notices of the Royal Astronomical Society
N2  - 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.
KW  - stars: abundances
KW  - stars: AGB and post-AGB
KW  - stars: mass-loss
KW  - stars: Wolf-Rayet
KW  - planetary nebulae: general
KW  - planetary nebulae: individual: PN G029.0+00.4
Y1  - 2013
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/35100
SN  - 0035-8711
SN  - 1365-2966
VL  - 430
IS  - 3
SP  - 2302
EP  - 2312
PB  - Oxford Univ. Press
CY  - Oxford
ER  -