Rotationally modulated variability and pulsations of the
He-rich star CPD-62 degrees 2124 with an extraordinarily strong
magnetic field

J 2017

Rotationally modulated variability and pulsations of the He-rich star CPD-62 degrees 2124 with an extraordinarily strong magnetic field

HUBRIG, Swetlana, Zdeněk MIKULÁŠEK, Alexandr F. KHOLTYGIN, Ilyin ILIEV, Marcus SCHÖLLER et. al.

Základní údaje

Originální název

Rotationally modulated variability and pulsations of the He-rich star CPD-62 degrees 2124 with an extraordinarily strong magnetic field

Autoři

HUBRIG, Swetlana (276 Německo), Zdeněk MIKULÁŠEK (203 Česká republika, garant, domácí), Alexandr F. KHOLTYGIN (643 Rusko), Ilyin ILIEV (100 Bulharsko), Marcus SCHÖLLER (276 Německo), Silvia P. JARVINEN (246 Finsko), R.D. SCHOLZ (276 Německo) a Miloslav ZEJDA (203 Česká republika, domácí)

Vydání

Monthly Notices of the Royal Astronomical Society, Oxford, OXFORD UNIV PRESS, 2017, 0035-8711

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10308 Astronomy

Stát vydavatele

Velká Británie a Severní Irsko

Utajení

není předmětem státního či obchodního tajemství

Impakt faktor

Impact factor: 5.194

Kód RIV

RIV/00216224:14310/17:00095344

Organizační jednotka

Přírodovědecká fakulta

DOI

http://dx.doi.org/10.1093/mnras/stx1994

UT WoS

000413765800032

Klíčová slova anglicky

stars: chemically peculiar; stars: early-type; stars: individual: CPD-62 degrees 2124; stars: magnetic field; stars: oscillations

Štítky

NZ, rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 11. 4. 2018 14:42, Ing. Nicole Zrilić

Anotace

V originále

A longitudinal magnetic field with a strength of 5.2 kG was recently detected in CPD -62 degrees 2124, which has a fractional main-sequence lifetime of about 60 per cent. Strongly magnetic early-B type chemically peculiar stars in an advanced evolutionary state are of special interest to understand the evolution of the angular momentum and spin-down time-scales in the presence of a global magnetic field. We made use of 17 FORS 2 low-resolution spectropolarimetric observations and 844 ASAS3 photometric measurements for the determination of the rotation period, pulsationsand the magnetic field geometry of the star. We calculated periodograms and applied phenomenological models of photometric, spectral and spectropolarimetric variability. We found that all quantities studied, specifically equivalent widths, the mean longitudinal magnetic field < B-z > and the flux in the V filter, vary with the same period P = 2.628 d, which was identified as the rotation period. The observed variations can be fully explained by a rigidly rotating main-sequence star with an uneven distribution of chemical elements, photometric spots and a stable, nearly dipolar magnetic field with a polar field strength of about 21 kG, frozen into the body of the star. The magnetic field of CPD -62 degrees 2124 is tilted to the rotation axis by beta = 28 degrees +/- 7 degrees, while the inclination of the rotation axis towards the line of sight is only i = 20 degrees +/- 5 degrees. In the acquired FORS 2 spectra, we detect short-term line profile variations indicating the presence of beta Cephei type pulsations. As of today, no other pulsating star of this type is known to possess such a strong magnetic field.

Návaznosti

GA16-01116S, projekt VaV

Název: Atmosféry a okolohvězdné prostředí magnetických horkých hvězd

Investor: Grantová agentura ČR, Atmosféry a okolohvězdné prostředí magnetických horkých hvězd

Citovat

HUBRIG, Swetlana, Zdeněk MIKULÁŠEK, Alexandr F. KHOLTYGIN, Ilyin ILIEV, Marcus SCHÖLLER, Silvia P. JARVINEN, R.D. SCHOLZ a Miloslav ZEJDA. Rotationally modulated variability and pulsations of the He-rich star CPD-62 degrees 2124 with an extraordinarily strong magnetic field. Monthly Notices of the Royal Astronomical Society. Oxford: OXFORD UNIV PRESS, 2017, roč. 472, č. 1, s. 400-408. ISSN 0035-8711. Dostupné z: https://dx.doi.org/10.1093/mnras/stx1994.

@article{1401959,
   author = {Hubrig, Swetlana and Mikulášek, Zdeněk and Kholtygin, Alexandr F. and Iliev, Ilyin and Schöller, Marcus and Jarvinen, Silvia P. and Scholz, R.D. and Zejda, Miloslav},
   article_location = {Oxford},
   article_number = {1},
   doi = {http://dx.doi.org/10.1093/mnras/stx1994},
   keywords = {stars: chemically peculiar; stars: early-type; stars: individual: CPD-62 degrees 2124; stars: magnetic field; stars: oscillations},
   language = {eng},
   issn = {0035-8711},
   journal = {Monthly Notices of the Royal Astronomical Society},
   title = {Rotationally modulated variability and pulsations of the He-rich star CPD-62 degrees 2124 with an extraordinarily strong magnetic field},
   volume = {472},
   year = {2017}
}

TY  - JOUR
ID  - 1401959
AU  - Hubrig, Swetlana - Mikulášek, Zdeněk - Kholtygin, Alexandr F. - Iliev, Ilyin - Schöller, Marcus - Jarvinen, Silvia P. - Scholz, R.D. - Zejda, Miloslav
PY  - 2017
TI  - Rotationally modulated variability and pulsations of the He-rich star CPD-62 degrees 2124 with an extraordinarily strong magnetic field
JF  - Monthly Notices of the Royal Astronomical Society
VL  - 472
IS  - 1
SP  - 400-408
EP  - 400-408
PB  - OXFORD UNIV PRESS
SN  - 00358711
KW  - stars: chemically peculiar
KW  - stars: early-type
KW  - stars: individual: CPD-62 degrees 2124
KW  - stars: magnetic field
KW  - stars: oscillations
N2  - A longitudinal magnetic field with a strength of 5.2 kG was recently detected in CPD -62 degrees 2124, which has a fractional main-sequence lifetime of about 60 per cent. Strongly magnetic early-B type chemically peculiar stars in an advanced evolutionary state are of special interest to understand the evolution of the angular momentum and spin-down time-scales in the presence of a global magnetic field. We made use of 17 FORS 2 low-resolution spectropolarimetric observations and 844 ASAS3 photometric measurements for the determination of the rotation period, pulsationsand the magnetic field geometry of the star. We calculated periodograms and applied phenomenological models of photometric, spectral and spectropolarimetric variability. We found that all quantities studied, specifically equivalent widths, the mean longitudinal magnetic field < B-z > and the flux in the V filter, vary with the same period P = 2.628 d, which was identified as the rotation period. The observed variations can be fully explained by a rigidly rotating main-sequence star with an uneven distribution of chemical elements, photometric spots and a stable, nearly dipolar magnetic field with a polar field strength of about 21 kG, frozen into the body of the star. The magnetic field of CPD -62 degrees 2124 is tilted to the rotation axis by beta = 28 degrees +/- 7 degrees, while the inclination of the rotation axis towards the line of sight is only i = 20 degrees +/- 5 degrees. In the acquired FORS 2 spectra, we detect short-term line profile variations indicating the presence of beta Cephei type pulsations. As of today, no other pulsating star of this type is known to possess such a strong magnetic field.
ER  -

HUBRIG, Swetlana, Zdeněk MIKULÁŠEK, Alexandr F. KHOLTYGIN, Ilyin ILIEV, Marcus SCHÖLLER, Silvia P. JARVINEN, R.D. SCHOLZ a Miloslav ZEJDA. Rotationally modulated variability and pulsations of the He-rich star CPD-62 degrees 2124 with an extraordinarily strong magnetic field. \textit{Monthly Notices of the Royal Astronomical Society}. Oxford: OXFORD UNIV PRESS, 2017, roč.~472, č.~1, s.~400-408. ISSN~0035-8711. Dostupné z: https://dx.doi.org/10.1093/mnras/stx1994.

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