A new calibration for the Blue Horizontal Branch
  We suggest a simple analytic approximation for magnitudes and hence distances
of Blue Horizontal Branch (BHB) stars in Sloan colours. Precedent formulations
do not offer a simple closed formula, nor do they cover the full dependences,
e.g. on metallicity. Further, using BHB star samples from the Sloan Digital Sky
Survey (SDSS) we validate our distance calibration directly on field stars
instead of globular clusters and assess the performance of other available
distance calibrations. Our method to statistically measure distances is
sufficiently accurate to measure the colour and metallicity dependence on our
sample and can be applied to other sets of stars or filters.
