An asteroseismic study of the O9V star HD 46202 from CoRoT space-based photometry

Briquet, Maryline; Aerts, C.; Baglin, A.; Nieva, M. F.; Degroote, P.; Przybilla, N.; Noels, A.; Schiller, F.; Vučković, M.; Oreiro, R.; Smolders, K.; Auvergne, M.; Baudin, F.; Catala, C.; Michel, E.; Samadi, R.

doi:10.1051/0004-6361/201015690

Cited by 89 publications

(122 citation statements)

References 46 publications

Supporting

Mentioning

113

Contrasting

Order By: Relevance

“…Some conclusions from earlier applications get even strengthened in retrospect by the present work: e.g. on chemical tagging in order to determine population membership of hypervelocity stars (Przybilla et al 2008a;Tillich et al 2009), the investigation of subtle abundance signatures to constrain supernova nucleosynthesis from binary supernova runaways (Przybilla et al 2008b;Irrgang et al 2010), or on coupling quantitative spectroscopy with asteroseismic analysis of pulsating OB stars observed with CoRoT (Briquet et al 2011). And, the methodology offers a high potential for future applications, that may facilitate many more facets of astrophysics to be studied at high confidence.…”

Section: Discussionmentioning

confidence: 67%

Present-day cosmic abundances

Nieva

Przybilla²

2012

A&A

Self Cite

431

506

View full text Add to dashboard Cite

Context. Early B-type stars are ideal indicators for present-day cosmic abundances since they preserve their pristine abundances and typically do not migrate far beyond their birth environments over their short lifetimes, in contrast to older stars like the Sun. They are also unaffected by depletion onto dust grains, unlike the cold/warm interstellar medium (ISM) or H ii regions. Aims. A carefully selected sample of early B-type stars in OB associations and the field within the solar neighbourhood is studied comprehensively. Quantitative spectroscopy is used to characterise their atmospheric properties in a self-consistent way. Present-day abundances for the astrophysically most interesting chemical elements are derived in order to investigate whether a present-day cosmic abundance standard can be established. Methods. High-resolution and high-S/N FOCES, FEROS and ELODIE spectra of well-studied sharp-lined early B-type stars are analysed in non-LTE. Line-profile fits based on extensive model grids and an iterative analysis methodology are used to constrain stellar parameters and elemental abundances at high accuracy and precision. Atmospheric parameters are derived from the simultaneous establishment of independent indicators, from multiple ionization equilibria and the Stark-broadened hydrogen Balmer lines, and they are confirmed by reproduction of the stars' global spectral energy distributions. Results. Effective temperatures are constrained to 1-2% and surface gravities to less than 15% uncertainty, along with accurate rotational, micro-and macroturbulence velocities. Good agreement of the resulting spectroscopic parallaxes with those from the new reduction of the Hipparcos catalogue is obtained. Absolute values for abundances of He, C, N, O, Ne, Mg, Si and Fe are determined to better than 25% uncertainty. The synthetic spectra match the observations reliably over almost the entire visual spectral range. Three sample stars, γ Ori, o Per and θ 1 Ori D, are identified as double-lined, indicating the presence of an early/mid B-type companion. Conclusions. A present-day cosmic abundance standard is established from a sample of 29 early B-type stars, indicating abundance fluctuations of less than 10% around the mean. Our results (i) resolve the long-standing discrepancy between a chemical homogeneous gas-phase ISM and a chemically inhomogeneous young stellar component out to several hundred parsec from the Sun, (ii) facilitate the amount of heavy elements locked up in the interstellar dust to be constrained precisely -the results imply that carbonaceous dust is largely destroyed inside the Orion H ii region, unlike the silicates, and that graphite is only a minority species in interstellar dust -, (iii) show that the mixing of CNO-burning products in the course of massive star evolution follows tightly the predicted nuclear path, (iv) provide reliable present-day reference points for anchoring Galactic chemical evolution models to observation, and (v) imply that the Sun has migrated outwards from the inne...

show abstract

Section: Discussionmentioning

confidence: 67%

Present-day cosmic abundances

Nieva

Przybilla²

2012

A&A

Self Cite

431

506

View full text Add to dashboard Cite

show abstract

“…Ribas et al (2000) used eclipsing binaries to show that α increases with mass, but Claret (2007) found that α = 0.2 could reproduce correctly the properties of 3 < M < 30 M stars. Using asteroseismology, Briquet et al (2007) determined α = 0.44 ± 0.07 for the B2IV star θ Oph and Briquet et al (2011) obtained α = 0.1 ± 0.05 for the O9V star HD 46202. One of the main reasons for these differences is that it is usually the extent of the convective core that is constrained from observations.…”

Section: The Main Sequence Widthmentioning

confidence: 99%

A comparison of evolutionary tracks for single Galactic massive stars

Martins

Palacios

2013

A&A

134

121

View full text Add to dashboard Cite

Context. The evolution of massive stars is not fully understood. The relation between different types of evolved massive stars is not clear, and the role of factors such as binarity, rotation or magnetism needs to be quantified. Aims. Several groups make available the results of 1D single stellar evolution calculations in the form of evolutionary tracks and isochrones. They use different stellar evolution codes for which the input physics and its implementation varies. In this paper, we aim at comparing the currently available evolutionary tracks for massive stars. We focus on calculations aiming at reproducing the evolution of Galactic stars. Our main goal is to highlight the uncertainties on the predicted evolutionary paths. Methods. We compute stellar evolution models with the codes MESA and STAREVOL. We compare our results with those of four published grids of massive stellar evolution models (Geneva, STERN, Padova and FRANEC codes). We first investigate the effects of overshooting, mass loss, metallicity, chemical composition. We subsequently focus on rotation. Finally, we compare the predictions of published evolutionary models with the observed properties of a large sample of Galactic stars. Results. We find that all models agree well for the main sequence evolution. Large differences in luminosity and temperatures appear for the post main sequence evolution, especially in the cool part of the Hertzsprung-Russell (HR) diagram. Depending on the physical ingredients, tracks of different initial masses can overlap, rendering any mass estimate doubtful. For masses between 7 and 20 M , we find that the main sequence width is slightly too narrow in the Geneva models including rotation. It is (much) too wide for the (STERN) FRANEC models. This conclusion is reached from the investigation of the HR diagram and from the evolution of the surface velocity as a function of surface gravity. An overshooting parameter α between 0.1 and 0.2 in models with rotation is preferred to reproduce the main sequence width. Determinations of surface abundances of carbon and nitrogen are partly inconsistent and cannot be used at present to discriminate between the predictions of published tracks. For stars with initial masses larger than about 60 M , the FRANEC models with rotation can reproduce the observations of luminous O supergiants and WNh stars, while the Geneva models remain too hot.

show abstract

“…CoRoT observations show further examples of the variability of O stars and several frequencies in light curves were found, which were not predicted to be unstable modes by the OPAL and OP seismic models (cf. Blomme et al 2011;Briquet et al 2011;Degroote et al 2010;Mahy et al 2011).…”

Section: Oscillation Spectra Of Early-type Starsmentioning

confidence: 99%

Seismic models of O and B stars with Kurucz’s opacity data

Cugier

2014

A&A

View full text Add to dashboard Cite

Aims. We investigated seismic models of O and B stars calculated with the new Kurucz opacities implemented in the Opacity Project (OP) and Rogers & Iglesias OPAL opacity tables (OPAL). Methods. We studied the problem using Dziembowski's computer codes for linear, nonadiabatic, and nonradial oscillations. We considered seismic models of main sequence (MS) stars for different chemical compositions of elements in the mass-range 9 ≤ M ≤ 70 M . Results. The new opacity bump at lg T ≈ 5.06 that occurs in Kurucz's data influences evolutionary tracks mainly for M ≥ 30 M and markedly changes the driving zone for pulsations of stars in the whole mass range studied. We obtained no unstable oscillation modes for models corresponding to the abundance parameter Z ≤ 0.013 and only unstable low-frequency g-modes for 0.013 < Z ≤ 0.021. Conclusions. The opacity bump at lg T ≈ 5.3 should be significantly larger than the opacity bump at lg T ≈ 5.06 to drive pulsations of B stars in low-degree p-modes. Models with an increased OPAL (or OP) opacity bump at lg T ≈ 5.3 by a factor of about 1.7 have sufficiently large driving zones to excite modes in the β Cephei frequency-domain for 0.003 ≤ Z ≤ 0.021. These values of Z are in a good agreement with those derived spectroscopically for stars in the Galaxy and Magellanic Clouds.

show abstract

An asteroseismic study of the O9V star HD 46202 from CoRoT space-based photometry

Cited by 89 publications

References 46 publications

Present-day cosmic abundances

Present-day cosmic abundances

A comparison of evolutionary tracks for single Galactic massive stars

Seismic models of O and B stars with Kurucz’s opacity data

Contact Info

Product

Resources

About