2010
Modelling the light variability of the Ap star epsilon Ursae Majoris
SHULYAK, Denis; Jiří KRTIČKA; Zdeněk MIKULÁŠEK; Oleg KOCHUKHOV; Theresa LÜFTINGER et al.Základní údaje
Originální název
Modelling the light variability of the Ap star epsilon Ursae Majoris
Název česky
Modelování světelné proměnnosti Ap hvězdy epsilon UMa
Název anglicky
Modelling the light variability of the Ap star epsilon Ursae Majoris
Autoři
SHULYAK, Denis; Jiří KRTIČKA; Zdeněk MIKULÁŠEK; Oleg KOCHUKHOV a Theresa LÜFTINGER
Vydání
Astronomy and Astrophysics, Les Ulis Cedex, France, EDP Sciences, 2010, 0004-6361
Další údaje
Jazyk
čeština
Typ výsledku
Článek v odborném periodiku
Obor
10308 Astronomy
Stát vydavatele
Francie
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Impakt faktor
Impact factor: 4.425
Označené pro přenos do RIV
Ano
Kód RIV
RIV/00216224:14310/10:00040632
Organizační jednotka
Přírodovědecká fakulta
UT WoS
Klíčová slova česky
hvězdy: chemicky pekuliární; hvězdy: proměnné: hvězdy: atmosféry; hvězdy: jednotlivé: epsilon UMa
Klíčová slova anglicky
stars: chemically peculiar; stars: variables: general; stars: atmospheres; stars: individual: epsilon UMa
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 10. 2. 2011 17:30, prof. Mgr. Jiří Krtička, Ph.D.
V originále
Aims. We simulate the light variability of the Ap star epsilon UMa using the observed surface distributions of Fe, Cr, Ca, Mn, Mg, Sr, and Ti obtained with the help of the Doppler imaging technique. Methods. Using all photometric data available, we specified light variations of epsilon UMa modulated by its rotation from far UV to IR. We employed the LLmodels stellar model atmosphere code to predict the light variability in different photometric systems. Results. The rotational period of epsilon UMa is refined to 5.088631(18) day. It is shown that the observed light variability can be explained as a result of the redistribution of radiative flux from the UV spectral region to the visual caused by the inhomogeneous surface distribution of chemical elements. Among seven mapped elements, only Fe and Cr contribute significantly to the amplitude of the observed light variability. In general, we find very good agreement between theory and observations. We confirm the important role of Fe and Cr in determining the magnitude of the well-known depression around 5200 A by analyzing the peculiar a-parameter. Finally, we show that the abundance spots of considered elements cannot explain the observed variabilities in near UV and beta index, which probably have other causes. Conclusions. The inhomogeneous surface distribution of chemical elements can explain most of the observed light variability of the A-type CP star epsilon UMa.
Anglicky
Aims. We simulate the light variability of the Ap star epsilon UMa using the observed surface distributions of Fe, Cr, Ca, Mn, Mg, Sr, and Ti obtained with the help of the Doppler imaging technique. Methods. Using all photometric data available, we specified light variations of epsilon UMa modulated by its rotation from far UV to IR. We employed the LLmodels stellar model atmosphere code to predict the light variability in different photometric systems. Results. The rotational period of epsilon UMa is refined to 5.088631(18). It is shown that the observed light variability can be explained as a result of the redistribution of radiative flux from the UV spectral region to the visual caused by the inhomogeneous surface distribution of chemical elements. Among seven mapped elements, only Fe and Cr contribute significantly to the amplitude of the observed light variability. In general, we find very good agreement between theory and observations. We confirm the important role of Fe and Cr in determining the magnitude of the well-known depression around 5200 A by analyzing the peculiar a-parameter. Finally, we show that the abundance spots of considered elements cannot explain the observed variabilities in near UV and beta index, which probably have other causes. Conclusions. The inhomogeneous surface distribution of chemical elements can explain most of the observed light variability of the A-type CP star epsilon UMa.
Návaznosti
| IAA301630901, projekt VaV |
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| MEB061014, projekt VaV |
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