New observations of chemically peculiar stars with ESPaDOnS

Khalack, V.; Yameogo, B.; Thibeault, C.; Leblanc, F.

doi:10.1017/s1743921314002257

Cited by 2 publications

(2 citation statements)

References 3 publications

(4 reference statements)

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“…Ap/Bp stars often exhibit chemical peculiarities and slow rotation (e.g., Zorec & Royer 2012;Netopil et al 2017;Ryabchikova & Romanovskaya 2017;Hümmerich et al 2020). These stars also display vertical stratification of the abundance of several chemical species, indicating distinct chemical and temperature stratification in their photospheres (e.g., Savanov & Kochukhov 1998;Zverko et al 2005;Khalack et al 2014). In contrast to more massive magnetic stars (with spectral types earlier than B5), the magnetic field geometry and evolution of Ap/Bp stars depend on their mass (e.g., Mathys et al 1997;Hubrig et al 2000 In the top row of Figure 10, we presented the pair-wise relationships between the fitting parameters of SLF variability for our Ap/Bp subsample; each star is color-coded by its luminosity.…”

Section: Stochastic Low-frequency Variabilitymentioning

confidence: 99%

Variability of Magnetic Hot Stars from the TESS Observations

Shen,

Li,

Abdusamatjan

et al. 2023

ApJ

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Magnetic hot stars refer to stars that have effective temperatures approximately in the range from 7000–50,000 K, and with large-scale globally organized magnetic fields. These magnetic fields exhibit strengths ranging from tens of Gauss to tens of kilo-Gauss. They are key in understanding the effects caused by magnetic fields in the stellar evolution. However, there are only three magnetic hot stars studied via a combination of spectropolarimetric and asteroseismic modeling. Combined with Transiting Exoplanet Survey Satellite sectors 1–56 data sets, we provided a photometric variability and stochastic low-frequency (SLF) variability study of 118 magnetic hot stars. Nine new rotating variable stars are identified. Using the Bayesian Markov Chain Monte Carlo framework, we fitted the morphologies of SLF variability for magnetic hot stars. Our analysis reveals that the magnetic hot stars in our sample have γ < 5.5 with the vast majority having 1 ≤ γ ≤ 3. The ν char is primarily in the ranges of 0 day−1 < ν char < 6.3 day−1. The amplitude of SLF variability, log α 0, shows a dominant distribution ranging from 0.8–3. No significant correlations are observed between the luminosity and fitting parameters, suggesting no clear dependence of SLF variability on stellar mass for our sample of magnetic hot stars with masses between approximately 1.5 M ⊙ < M < 20 M ⊙. We found a significant negative correlation between the B p and ν char. This suppression effect of magnetic fields on ν char may be a result of their inhibition of macroturbulence.

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Section: Stochastic Low-frequency Variabilitymentioning

confidence: 99%

Variability of Magnetic Hot Stars from the TESS Observations

Shen,

Li,

Abdusamatjan

et al. 2023

ApJ

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“…The obtained stellar atmosphere parameters have been used to calculate homogeneous stellar atmosphere models, which were employed to perform an abundance analysis of HD 22920, HD 23878, HD 95608, HD 116235 and HD 186568 [28,29,38] with the help of the modied ZEEMAN2 code [24,25]. Among the studied CP stars, signatures of vertical stratication of silicon and chromium abundances were found in HD 22920 [29], and of iron and chromium abundances in HD 95608 and HD 116235 [28,38]. in a single exposure [11].…”

Section: Espadons Acquires High Resolution (R = 65000)mentioning

confidence: 99%

Project VeSElkA: Vertical Stratification of Element Abundances in CP stars

Khalack

Leblanc

2015

Adv.Astron.Spa.Physics

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A new research project on spectral analysis which aims to characterize the vertical stratication of element abundances in stellar atmospheres of chemically peculiar (CP) stars, is discussed in detail. Some results on detection of vertical abundance stratication in several slowly rotating main sequence CP stars are presented and considered as an indicator of the eectiveness of the atomic diusion mechanism responsible for the observed peculiarities of chemical abundances. This study is carried out in the frame of Project VeSElkA (Vertical Stratication of Elements Abundance) for which 34 slowly rotating CP stars have been observed with the ESPaDOnS spectropolarimetre at CFHT.

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New observations of chemically peculiar stars with ESPaDOnS

Cited by 2 publications

References 3 publications

Variability of Magnetic Hot Stars from the TESS Observations

Variability of Magnetic Hot Stars from the TESS Observations

Project VeSElkA: Vertical Stratification of Element Abundances in CP stars

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