High-precision CoRoT space photometry and fundamental parameter determination of the B2.5V star HD48977.

We present the CoRoT light curve of the bright B2.5V star HD48977 observed during a short run of the mission in 2008, as well as a high-resolution spectrum gathered with the HERMES spectrograph at the Mercator telescope. We use several time series analysis tools to explore the nature of the variations in the light curve.We performed a detailed analysis of the spectrum of the star to determine its fundamental parameters and its element abundances. We find a large number of high-order g-modes, and one rotationally induced frequency. We find stable low-amplitude frequencies in the p-mode regime as well. We conclude that HD48977 is a new slowly pulsating B star with fundamental parameters found to be T_eff = 20 000 ± 1000 K and log g = 4.2 ± 0.1. The element abundances are similar to those found for other B stars in the solar neighbourhood. HD48977 was observed during a short run of the CoRoT satellite implying that the frequency precision is insufficient to perform asteroseismic modelling of the star. Nevertheless, we show that a longer time series of this star would be promising for such modelling. Our present study contributes to a detailed mapping of the instability strips of B stars in view of the dominance of g-mode pulsations in the star, several of which occur in the gravito-inertial regime [ABSTRACT FROM AUTHOR]