KRTIČKA, Jiří, Zdeněk MIKULÁŠEK, Milan PRVÁK, E. NIEMCZURA, F. LEONE and G. WADE. Distorted surfaces of magnetic helium-peculiar stars: an application to a Cen. Monthly Notices of the Royal Astronomical Society. Oxford: Oxford University Press, 2020, vol. 493, No 2, p. 2140-2148. ISSN 0035-8711. Available from: https://dx.doi.org/10.1093/mnras/staa378.
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Basic information
Original name Distorted surfaces of magnetic helium-peculiar stars: an application to a Cen
Authors KRTIČKA, Jiří (203 Czech Republic, guarantor, belonging to the institution), Zdeněk MIKULÁŠEK (203 Czech Republic, belonging to the institution), Milan PRVÁK (203 Czech Republic, belonging to the institution), E. NIEMCZURA, F. LEONE and G. WADE.
Edition Monthly Notices of the Royal Astronomical Society, Oxford, Oxford University Press, 2020, 0035-8711.
Other information
Original language English
Type of outcome Article in a journal
Field of Study 10308 Astronomy
Country of publisher United Kingdom of Great Britain and Northern Ireland
Confidentiality degree is not subject to a state or trade secret
WWW URL
Impact factor Impact factor: 5.287
RIV identification code RIV/00216224:14310/20:00114466
Organization unit Faculty of Science
Doi http://dx.doi.org/10.1093/mnras/staa378
UT WoS 000525996700042
Keywords in English stars: chemically peculiar; stars: early type; stars: individual: a Cen; stars: variables: general
Tags rivok
Tags International impact, Reviewed
Changed by Changed by: Mgr. Marie Šípková, DiS., učo 437722. Changed: 13/11/2020 11:48.
Abstract
Helium-peculiar magnetic chemically peculiar stars show variations of helium abundance across their surfaces. As a result of associated atmospheric scale height variations, the stellar surface becomes distorted, with helium-rich regions dented inwards. Effectively, on top of flux variations due to opacity effects, the depressed helium-rich surface regions become less bright in the optical regions and brighter in the ultraviolet. We study the observational effects of the aspherical surface on the light curves of a Cen. We simulate the light curves of this star adopting surface distributions of He, N, O, Si, and Fe derived from Doppler mapping and introducing the effect of distortion proportional to helium abundance. We show that while most of the optical and UV variations of this star result from flux redistribution due to the non-uniform surface distributions of helium and iron, the reduction of light variations due to the helium-related surface distortion leads to a better agreement between simulated optical light curves and the light curves observed with the BRITE satellites.
Links
GA18-05665S, research and development projectName: Ztráta hmoty v pozdních fázích vývoje hmotných hvězd
Investor: Czech Science Foundation
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