Nonthermal Optical Transients from Relativistic Fireballs

A general upper bound is derived on the total energy in incoherent nonthermal transients at frequency $\nu$ from relativistic fireballs with bulk Lorentz factors $\Gamma$ and observed duration $\Delta t$, and shown to be about ${10}^{-2\mathrm{}}[\Gamma \nu \Delta t{]}^3\mathrm{ergs}$. It is suggested that detection in the optical can be achieved with the next generation of ground based gamma ray telescopes and/or small optical telescopes. Phenomena within the Galaxy such as accretion disk flares and neutron star magnetospheric discharges might be discovered in this way.