Modelling of the ultraviolet and visual SED variability in the hot magnetic Ap star CU Virginis

The spectral energy distribution (SED) in chemically peculiar stars may be significantly affected by their abundance anomalies. This study aims to identify the processes that determine the SED and its variability in the UV and visual spectral domains of the helium-weak star CU Vir. The authors used...

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Bibliographic Details
Published in:Astronomy and astrophysics (Berlin) 2012-01, Vol.537, p.1-1
Main Authors: Krticka, J, Mikulasek, Z, Lueftinger, T, Shulyak, D, Zverko, J, Ziznovsky, J, Sokolov, N A
Format: Article
Language:English
Online Access:Get full text
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Summary:The spectral energy distribution (SED) in chemically peculiar stars may be significantly affected by their abundance anomalies. This study aims to identify the processes that determine the SED and its variability in the UV and visual spectral domains of the helium-weak star CU Vir. The authors used the TLUSTY model atmospheres calculated for the appropriate surface chemical composition to obtain the emergent flux and predict the rotationally modulated flux variability of the star. The visual and UV light variability of CU Vir is caused by the flux redistribution from the far UV to near UV and visible regions, in homogeneous distribution of the elements and stellar rotation. Bound-free transitions of silicon and bound-bound transitions of iron and chromium contribute the most to the flux redistribution. This mechanism can explain most of the rotationally modulated light variations in the filters centred on the Paschen continuum and on the UV continuum of the star CU Vir.
ISSN:0004-6361
1432-0746