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The β Cephei star HD 180642 was observed by the CoRoT satellite during a run of 156 days in 2007. The space white light photometry revealed the rich frequency spectrum of the star (Degroote et al. 2009). In the present study, we provide additional information on the target, based on both ground‐based multi‐colour photometry and high‐resolution spectroscopy. We place our object in the (Teff, log g) diagram. In addition, we derive the chemical abundances of several elements as well as the metallicity of HD 180642. Finally, we put constraints on the identification of some modes. All these observational constraints will be used to compute stellar models of the target.

The recent downward revision of the solar CNO photospheric abundances now leads to severe inconsistencies between theoretical models for the Sun's internal structure and the results of helioseismology. There have been claims that the solar Ne abundance may be underestimated and that an increase in this ill‐defined quantity could alleviate (or even completely solve) this problem. To address the validity of this hypothesis, we present a fully homogeneous non‐LTE abundance analysis of the optical Ne I/II lines in a sample of 18 nearby B‐type stars. Our very preliminary results point towards a mean neon abundance slightly higher than the new solar value, but apparently insufficient by itself to restore the agreement between the solar models and the helioseismological constraints.

Evolutionary models for massive stars which take into account rotational mixing effects do not predict any core‐processed material at the surface of B dwarfs with low rotational velocities. We present a detailed and fully homogeneous non‐LTE abundance analysis of a sample of largely unevolved B stars which points to the existence of a population of intrinsically slowly‐rotating, yet nitrogen‐rich objects contrary to theoretical expectations. These observations are discussed in relation to the boron content and the (weak) magnetic field detected in some targets.