  By using two-fluid model the effect of impurities on the transition
temperature of a dipolar trapped Bose gas is investigated. By treating Gaussian
spatial correlation for impurities from the interaction modified spectra of the
system, the formula for the shift of transition temperature is derived. The
shift of the transition temperature contains essentially three contributions
due to contact, dipole-dipole and impurity interactions. Applying our results
to Dipolar Bose gases show that the shift of the transition temperature due to
impurities could be measured for isotropic trap (dipole-dipole contributions is
zero) and Feshbach resonance technique (contact potential contribution is
negligible).
