Several possible models have been suggested to explain the observed distribution of gamma-ray bursts: heliocentric distributions such as the Oort cloud, large galactic halos, and cosmological models. We report here on an investigation into the implications of the Burst and Transient Source Experiment (BATSE) gamma-ray burst distribution (Meegan et al. 1992a) data on the possible heliocentric origin of gamma-ray bursts. We find no statistically significant anisotropy in the angular distribution of the bursts in a Sun-referenced coordinate system; there is no dipole moment in the direction of the Sun, and no quadrupole moment associated with the ecliptic plane. We have employed direct analytic calculations and Monte Carlo simulations of sources in the Oort cloud to constrain possible heliocentric burst distributions. These can produce distributions consistent with the observed angular isotropy, [V/V(max)], and the observed C/C(min) distribution of BATSE, and provide limits to burst energy of a few times approximately 10(27) ergs. However, the agreement of the heliocentric C/C(min) distributions with the BATSE data is attributable to the relatively limited sampling of strong, nearby bursts. These bursts are known from observation to be homogeneously distributed, yet the density of sources in the Oort cloud is not constant in this region. Integral number-intensity distributions from the Oort cloud for larger numbers of bursts cannot reproduce the known homogeneity of the strong bursts without modification to the computed cometary number density and are therefore unlikely explanations of the gamma-ray burst distribution.
