  Preliminary results on $\rho(770)^0$ and $f_{0}(980)$ production at
mid-rapidity using the mixed-event technique are presented. The $\rho^0$ and
$f_0$ measurements via their hadronic decay channel in minimum bias pp and
peripheral Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV were performed using
the STAR detector at RHIC. This is the first direct measurement of $\rho^0(770)
\to \pi^+\pi^-$ and $f_0(980) \to \pi^+\pi^-$ in heavy-ion collisions. The
$\rho^0$ mass is transverse momentum dependent and significantly shifted in
minimum bias pp and peripheral Au+Au interactions. The modifications of masses,
widths and line shapes of short-lived resonances due to phase space and
dynamical effects are discussed. The $\rho^0/\pi^-$ and the $f_0/\pi^-$ ratios
are compared to measurements in pp and e$^{+}$e$^{-}$ interactions at various
energies.
