We calculate the equation of state for degenerate quark matter to leading
order in hard-dense-loop (HDL) perturbation theory. We solve the
Tolman-Oppenheimer-Volkov equations to obtain the mass-radius relation for
dense quark stars. Both the perturbative QCD and the HDL equations of state
have a large variation with respect to the renormalization scale for quark
chemical potential below 1 GeV which leads to large theoretical uncertainties
in the quark star mass-radius relation.Comment: 7 pages, 3 figure