Photometric signatures of corotating magnetospheres of hot
stars governed by higher-order magnetic multipoles

J 2022

Photometric signatures of corotating magnetospheres of hot stars governed by higher-order magnetic multipoles

KRTIČKA, Jiří; Zdeněk MIKULÁŠEK; Petr KURFÜRST a Mary E. OKSALA

Základní údaje

Originální název

Photometric signatures of corotating magnetospheres of hot stars governed by higher-order magnetic multipoles

Autoři

KRTIČKA, Jiří; Zdeněk MIKULÁŠEK; Petr KURFÜRST a Mary E. OKSALA

Vydání

Astronomy & Astrophysics, EDP Sciences, 2022, 0004-6361

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10308 Astronomy

Stát vydavatele

Francie

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Impakt faktor

Impact factor: 6.500

Označené pro přenos do RIV

Ano

Kód RIV

RIV/00216224:14310/22:00125321

Organizační jednotka

Přírodovědecká fakulta

Klíčová slova anglicky

stars: magnetic field; stars: chemically peculiar; stars: early-type; circumstellar matter; stars: variables: general

Štítky

14312040, rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 25. 3. 2022 11:11, Mgr. Marie Novosadová Šípková, DiS.

Anotace

V originále

The light curves of magnetic, chemically peculiar stars typically show periodic variability due to surface spots that in most cases can be modeled by low-order harmonic expansion. However, high-precision satellite photometry reveals tiny complex features in the light curves of some of these stars that are difficult to explain as caused by a surface phenomenon under reasonable assumptions. These features might originate from light extinction in corotating magnetospheric clouds supported by a complex magnetic field dominated by higher-order multipoles. We aim to understand the photometric signatures of corotating magnetospheres that are governed by higher-order multipoles. We determined the location of magnetospheric clouds from the minima of the effective potential along the magnetic field lines for different orders of multipoles and their combination. From the derived magnetospheric density distribution, we calculated light curves accounting for absorption and subsequent emission of light. For axisymmetric multipoles, the rigidly rotating magnetosphere model is able to explain the observed tiny features in the light curves only when the higher-order multipoles dominate the magnetic field not only at the stellar surface, but even at the Kepler radius. However, even a relatively weak nonaxisymmetric component leads to warping of equilibrium surfaces. This introduces structures that can explain the tiny features observed in the light curves of chemically peculiar stars. The light emission contributes to the light variability only if a significant fraction of light is absorbed in the magnetosphere.

Citovat

KRTIČKA, Jiří; Zdeněk MIKULÁŠEK; Petr KURFÜRST a Mary E. OKSALA. Photometric signatures of corotating magnetospheres of hot stars governed by higher-order magnetic multipoles. Astronomy & Astrophysics. EDP Sciences, 2022, roč. 659, March, s. 1-14. ISSN 0004-6361. Dostupné z: https://doi.org/10.1051/0004-6361/202141997.

@article{1829821,
   author = {Krtička, Jiří and Mikulášek, Zdeněk and Kurfürst, Petr and Oksala, Mary E.},
   article_number = {March},
   doi = {https://doi.org/10.1051/0004-6361/202141997},
   keywords = {stars: magnetic field; stars: chemically peculiar; stars: early-type; circumstellar matter; stars: variables: general},
   language = {eng},
   issn = {0004-6361},
   journal = {Astronomy & Astrophysics},
   title = {Photometric signatures of corotating magnetospheres of hot stars governed by higher-order magnetic multipoles},
   url = {https://ui.adsabs.harvard.edu/abs/2022arXiv220111435K},
   volume = {659},
   year = {2022}
}

TY  - JOUR
ID  - 1829821
AU  - Krtička, Jiří - Mikulášek, Zdeněk - Kurfürst, Petr - Oksala, Mary E.
PY  - 2022
TI  - Photometric signatures of corotating magnetospheres of hot stars governed by higher-order magnetic multipoles
JF  - Astronomy & Astrophysics
VL  - 659
IS  - March
SP  - 1-14
EP  - 1-14
PB  - EDP Sciences
SN  - 00046361
KW  - stars: magnetic field
KW  - stars: chemically peculiar
KW  - stars: early-type
KW  - circumstellar matter
KW  - stars: variables: general
UR  - https://ui.adsabs.harvard.edu/abs/2022arXiv220111435K
N2  - The light curves of magnetic, chemically peculiar stars typically show periodic variability due to surface spots that in most cases can be modeled by low-order harmonic expansion. However, high-precision satellite photometry reveals tiny complex features in the light curves of some of these stars that are difficult to explain as caused by a surface phenomenon under reasonable assumptions. These features might originate from light extinction in corotating magnetospheric clouds supported by a complex magnetic field dominated by higher-order multipoles. We aim to understand the photometric signatures of corotating magnetospheres that are governed by higher-order multipoles. We determined the location of magnetospheric clouds from the minima of the effective potential along the magnetic field lines for different orders of multipoles and their combination. From the derived magnetospheric density distribution, we calculated light curves accounting for absorption and subsequent emission of light. For axisymmetric multipoles, the rigidly rotating magnetosphere model is able to explain the observed tiny features in the light curves only when the higher-order multipoles dominate the magnetic field not only at the stellar surface, but even at the Kepler radius. However, even a relatively weak nonaxisymmetric component leads to warping of equilibrium surfaces. This introduces structures that can explain the tiny features observed in the light curves of chemically peculiar stars. The light emission contributes to the light variability only if a significant fraction of light is absorbed in the magnetosphere.
ER  -

KRTIČKA, Jiří; Zdeněk MIKULÁŠEK; Petr KURFÜRST a Mary E. OKSALA. Photometric signatures of corotating magnetospheres of hot stars governed by higher-order magnetic multipoles. \textit{Astronomy \&{} Astrophysics}. EDP Sciences, 2022, roč.~659, March, s.~1-14. ISSN~0004-6361. Dostupné z: https://doi.org/10.1051/0004-6361/202141997.

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