  We report the real-time discovery of a fast radio burst (FRB 131104) with the
Parkes radio telescope in a targeted observation of the Carina dwarf spheroidal
galaxy. The dispersion measure of the burst is 779 cm$^{-3}$ pc, exceeding
predictions for the maximum line-of-sight Galactic contribution by a factor of
11. The temporal structure of the burst is characterized by an exponential
scattering tail with a timescale of 2.0$^{+0.8}_{-0.5}$ ms at 1582 MHz that
scales as frequency to the power $-$4.4$^{+1.6}_{-1.8}$ (all uncertainties
represent 95% confidence intervals). We bound the intrinsic pulse width to be
$<0.64$ ms due to dispersion smearing across a single spectrometer channel.
Searches in 78 hours of follow-up observations with the Parkes telescope reveal
no additional sporadic emission and no evidence for associated periodic radio
emission. We hypothesize that the burst is associated with the Carina dwarf
galaxy. Follow-up observations at other wavelengths are necessary to test this
hypothesis.
