Dipole of the Luminosity Distance: A Direct Measure of H(z)

We show that the dipole of the luminosity distance is a useful observational tool which allows us to determine the Hubble parameter as a function of redshift $H(z)$. We determine the number of supernovae needed to achieve a given precision for $H(z)$ and to distinguish between different models for dark energy. We analyze a sample of nearby supernovae and find a dipole consistent with the cosmic microwave background at a significance of more than $2\sigma$.