  We have constructed a comprehensive grid of 1540 metal line-blanketed, NLTE,
plane-parallel, hydrostatic model atmospheres for the basic parameters
appropriate to early B-type stars. The BSTAR2006 grid considers 16 values of
effective temperatures, 15,000 K <= Teff <= 30,000 K with 1,000 K steps, 13
surface gravities, 1.75 <= log g <= 4.75 with 0.25 dex steps, 6 chemical
compositions, and a microturbulent velocity of 2 km/s. The lower limit of log g
for a given effective temperature is set by an approximate location of the
Eddington limit. The selected chemical compositions range from twice to one
tenth of the solar metallicity and metal-free. Additional model atmospheres for
B supergiants (log g <= 3.0) have been calculated with a higher microturbulent
velocity (10 km/s) and a surface composition that is enriched in helium and
nitrogen, and depleted in carbon. This new grid complements our earlier
OSTAR2002 grid of O-type stars (Lanz & Hubeny, 2003, ApJS, 146, 417). The paper
contains a description of the BSTAR2006 grid and some illustrative examples and
comparisons. NLTE ionization fractions, bolometric corrections, radiative
accelerations, and effective gravities are obtained over the parameter range
covered by the grid. By extrapolating radiative accelerations, we have
determined an improved estimate of the Eddington limit in absence of rotation
between 55,000 and 15,000 K. The complete BSTAR2006 grid is available at the
TLUSTY website (http://nova.astro.umd.edu).
