  In 2010, the STAR Collaboration collected 38 million low-multiplicity
triggers for ultra-peripheral collision studies. We present new results
involving photonuclear interactions in ultra-peripheral relativistic heavy ion
collisions (UPCs), based on an analysis of 384,000 photoproduced pion pairs,
from $\rho$, $\omega$ and direct $\pi^+\pi^-$ pair production.The $\omega$
component is clearly visible through its interference with the $\rho$ peak. The
relative amplitudes of the three components have been measured, along with the
phase angle between the $\rho$ and $\omega$ components.
  Using a two-year (2010 and 2011) dataset, we explore higher mass final
states, and observe a $\pi^+\pi^-$ state with a mass of $1653 \pm 10$ MeV and a
width of $164\pm 15$ MeV (statistical errors only). The state is at least
roughly compatible with the $\rho_3(1690)$.
  The $\rho^0$ squared momentum transfer ($t$) spectrum exhibits a spectrum
with both coherent and incoherent prodution. The coherent component shows two
characteristic diffraction minima, with positions that are sensitive to the
hadronic radius of the gold nucleus.
