Mode Identification of the <i>β</i> Cephei star BW Vulpeculae

Aerts, C.; Hoolst, Tim Van; Mathias, P.

doi:10.1017/s0252921100036770

Cited by 18 publications

(11 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nota bene, both calculations provide the same values for T eff and log g and they agree very well with previously determined values (e.g. T eff = 23 227 K by Aerts et al 1995). …”

Section: Synthetic Spectrum For Bw Vulsupporting

confidence: 88%

“…It is unlikely that line doubling in BW Vul is caused by non-radial modes as Aerts et al (1995) demonstrated that this star pulsates in a radial mode. Therefore, it is far more likely that the line doubling originates from shock waves as described by Mathias et al (1998).…”

Section: Line Doublingmentioning

confidence: 94%

“…Recent studies of its pulsational behavior, applying the moment method (Aerts et al 1992) and the method of photometric amplitudes (e.g. Heynderickx et al 1994), show that it pulsates in the fundamental radial mode with up to 8 harmonics (Aerts et al 1995).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Abundances and radial velocity analysis of BW Vulpeculae

Stankov

Ilyin

Fridlund

2003

A&A

View full text Add to dashboard Cite

Abstract. We present the results of the analysis of 56échelle spectra of the β Cephei star BW Vulpeculae. The data were obtained during three nights with the SOFIN spectrograph at the Nordic Optical Telescope and cover a wavelength range from 3650 Å to 7340 Å. We compare the observed spectrum with a synthetic spectrum calculated from a model atmosphere for this star utilizing the program ATLAS9 by Kurucz. From this, we determine a projected rotational velocity, v sin i, of 24 km s −1 . Detailed spectral line identification and an abundance analysis for this star are performed. From these analyses we find that Ne, Si, He, and Ar are over-abundant in BW Vulpeculae, while the abundances for N, S, O, Fe, C, and Al are solar. Finally, a comparison of radial velocity curves from six different layers of BW Vulpeculae's atmosphere is presented, corresponding to the formation depths of different elements. We show that at least six of these layers move independently from each other.

show abstract

“…Nota bene, both calculations provide the same values for T eff and log g and they agree very well with previously determined values (e.g. T eff = 23 227 K by Aerts et al 1995). …”

Section: Synthetic Spectrum For Bw Vulsupporting

confidence: 88%

Section: Line Doublingmentioning

confidence: 94%

See 1 more Smart Citation

Abundances and radial velocity analysis of BW Vulpeculae

Stankov

Ilyin

Fridlund

2003

A&A

View full text Add to dashboard Cite

show abstract

“…This is justified because the amplitude of the harmonic is about 4 times lower than the one of f 1 . This type of approach turned out to be valid for the β Cep star BW Vul, for which the relative contribution of the first harmonic to the radial-velocity variation is also a factor near 1/4 of the one of the frequency itself (Aerts et al 1995). The results of the MM are given in Table 3.…”

Section: Multiperiodic Oscillationsmentioning

confidence: 99%

Disentangling component spectra of , a spectroscopic binary with a pulsating primary

Uytterhoeven

Briquet

Aerts

et al. 2005

A&A

Self Cite

View full text Add to dashboard Cite

Abstract. We analyse the complex short-term Si  line-profile variability of the spectroscopic binary β Cep star κ Sco after orbit subtraction, before and after spectral disentangling. We refine the known oscillation frequency of the star:and detect 2 f 1 . Variability is also found at frequencies near f 2 4.85 c d −1 and f 3 5.69 c d −1 or their aliases. These frequencies are not significant if we consider the spectra alone, but they survive our selection after the consideration that they were derived previously from independent ground-based and space photometry by different teams. Moreover, we find dominant variability in the equivalent width with a frequency in the interval [0.22, 0.30] c d −1 which we interpret as the rotational frequency f rot of the star. The complex window function does not allow us to determine definite values for f 2 , f 3 , f rot . The variability with f 1 is interpreted as a prograde non-radial oscillation mode with spherical wavenumbers ( , m) = (2, −1) or (1, −1). The additional frequencies are explained in terms of rotational modulation superposed to the main oscillation. We also point out that we cannot disprove the variability in κ Sco to originate from co-rotating structures. KOREL disentangling preserves the large-amplitude line-profile variability but its performance for complex low-amplitude variability remains to be studied in detail.

show abstract

“…As already indicated by the photometry, the dominant mode does not behave sinusoidally at all and v 1 has a peak-to-peak amplitude of about 90 km s −1 . This makes HD 180 642 the β Cephei star with the third largest peak-to-peak radial-velocity amplitude, BW Vul having ∼180 km s −1 (Crowe & Gillet 1989;Aerts et al 1995;Mathias et al 1998) and σ Sco having ∼110 km s −1 (Mathias et al 1991). More unusual is the presence of a so-called stillstand, i.e., a plateau at half the descending branch of the radial velocity curve.…”

Section: Frequency Analysismentioning

confidence: 99%

3.2 Ground-based observations

Lilensten¹,

Wit²,

Matthes³

2015

Earth’s Climate Response to a Changing Sun

View full text Add to dashboard Cite

The known β Cephei star HD 180 642 was observed by the CoRoT satellite in 2007. From the very high-precision light curve, its pulsation frequency spectrum could be derived for the first time (Degroote and collaborators). In this paper, we obtain additional constraints for forthcoming asteroseismic modeling of the target. Our results are based on both extensive ground-based multicolour photometry and high-resolution spectroscopy. We determine T eff = 24 500 ± 1000 K and log g = 3.45 ± 0.15 dex from spectroscopy. The derived chemical abundances are consistent with those for B stars in the solar neighbourhood, except for a mild nitrogen excess. A metallicity Z = 0.0099 ± 0.0016 is obtained. Three modes are detected in photometry. The degree is unambiguously identified for two of them: = 0 and = 3 for the frequencies 5.48694 d −1 and 0.30818 d −1 , respectively. The radial mode is non-linear and highly dominant with an amplitude in the U-filter about 15 times larger than the strongest of the other modes. For the third frequency of 7.36673 d −1 found in photometry, two possibilities remain: = 0 or 3. In the radial velocities, the dominant radial mode presents a so-called stillstand but no clear evidence of the existence of shocks is observed. Four low-amplitude modes are found in spectroscopy and one of them, with frequency 8.4079 d −1 , is identified as ( , m) = (3, 2). Based on this mode identification, we finally deduce an equatorial rotational velocity of 38 ± 15 km s −1 .

show abstract

Mode Identification of the β Cephei star BW Vulpeculae

Abstract: Abstract. We identify the pulsation mode of BW Vul by means of both the moment method and the method of photometric amplitudes and find a radial pulsation. We briefly study the non-linear behaviour of BW Vul.

Cited by 18 publications

References 3 publications

Abundances and radial velocity analysis of BW Vulpeculae

Abundances and radial velocity analysis of BW Vulpeculae

Disentangling component spectra of , a spectroscopic binary with a pulsating primary

3.2 Ground-based observations

Contact Info

Product

Resources

About