Intrinsic Color Indices of Early-Type Dwarf Stars
  Early-type stars are short lived and scarce in comparison with other types.
Based on the recently released catalogs of early type stars from the largest
LAMOST spectroscopic survey, the intrinsic colors of the stars with effective
temperature up to 32,000\,K are determined for the bands from ultraviolet to
infrared by using the blue-edge method. Analytic relations are derived for the
intrinsic color index with the effective temperature for the \emph{WISE},
2MASS, \emph{Gaia}, APASS, SDSS, Pan-STARRS1, and \emph{GALEX} bands. The
results are generally consistent with previous works. In addition, the
intrinsic colors of O-type dwarfs and OB supergiants are roughly estimated.
