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

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F17%3A00095344" target="_blank" >RIV/00216224:14310/17:00095344 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1093/mnras/stx1994" target="_blank" >http://dx.doi.org/10.1093/mnras/stx1994</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/stx1994" target="_blank" >10.1093/mnras/stx1994</a>

Result language

angličtina

Original language name

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

Original language description

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 &lt; B-z &gt; 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.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

<a href="/en/project/GA16-01116S" target="_blank" >GA16-01116S: Atmospheres and circumstellar environment of magnetic hot stars</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Monthly Notices of the Royal Astronomical Society

ISSN

0035-8711

e-ISSN

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Volume of the periodical

472

Issue of the periodical within the volume

1

Country of publishing house

GB - UNITED KINGDOM

Number of pages

9

Pages from-to

400-408

UT code for WoS article

000413765800032

EID of the result in the Scopus database

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