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Context. B-type stars are known to rotate at various velocities,
including very fast rotators near the critical velocity as the Be stars.
Aims. In this paper, we provide stellar models covering the mass range
between 1.7 to 15 M⊙, which includes the typical mass of
known Be stars, at Z = 0.014, 0.006, and 0.002 and for an extended range
of initial velocities on the zero-age main sequence.
Methods. We used the Geneva stellar-evolution code, including the
effects of shellular rotation, with a numerical treatment that has been improved so the
code can precisely track the variation in the angular momentum content of the star as it
changes under the influence of radiative winds and/or mechanical mass loss.
Results. We discuss the impact of the initial rotation rate on the
tracks in the Hertzsprung-Russell diagram, the main-sequence (MS) lifetimes, the evolution
of the surface rotation and abundances, as well as on the ejected masses of various
isotopes. Among the new results obtained from the present grid we find that 1)
fast-rotating stars with initial masses around 1.7 M⊙
present at the beginning of the core hydrogen-burning phase quite small convective cores
with respect to their slowly rotating counterparts. This fact may be interesting to keep
in mind in the framework of the asteroseismic studies of such stars. 2) The contrast
between the core and surface angular velocity is higher in slower rotating stars. Our
results are in agreement with the very few values obtained for B-type stars from
asteroseismology. 3) At Z = 0.002, the stars in the mass range of 1.7 to
3 M⊙ with a mean velocity on the MS of the order of
150 km s-1 show N/H enhancement superior to 0.2 dex at mid-MS, and
superior to 0.4 dex at the end of the MS phase. At solar metallicity the corresponding
values are below 0.2 dex at any time in the MS.
Conclusions. An extended database of stellar models containing 270
evolutionary tracks is provided to the community
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