Using the time-of-flight of gamma-ray bursts across the solar system, the Interplanetary Network of burst detectors has derived accurate locations for a number of bright bursts (see, e.g., Hack et al. 1994). Optical searches of these error boxes often show no bright object within them (Schaefer 1992, 1994). As examples, I show in Figures 21 and 22 the Interplanetary Network error boxes for GB790406 and GB791116. The brightest object in the first error box is 24.7 magnitudes in B (Motch et al. 1985), while the brightest object in the second error box is 21 magnitudes in B and R (Schaefer 1992).
The lack of bright optical counterparts for these bright bursts is easily explained if gamma-ray bursts come from high velocity neutron stars in the Galactic corona, since source distances of 100 - 500 kpc and the small surface area of neutron stars imply extremely faint emission in quiescence.
In contrast, the lack of bright optical "host" galaxies in the
Interplanetary Network error boxes of bright bursts is poses a severe
difficulty for cosmological models. The gamma-ray burst brightness
distribution implies that these bright bursts lie nearby, at redshifts
; any bright galaxy in the error box should be
easily visible. Their absence rules out cosmological models involving
either active galactic nuclei or a normal population of galaxies
(Schaefer 1992, 1994; Woods and Loeb 1995). It is even questionable
that the rate of gamma-ray bursts can be proportional to the amount of
blue light (Woods and Loeb 1995). This is a problem for the most
popular cosmological models, which involve the coalescence of neutron
star binaries (Paczynski 1986, Goodman 1986; Eichler et al. 1989;
Narayan, Piran, and Shemi 1991; Paczynski 1991; Piran, Narayan, and
Shemi 1992; Narayan, Paczynski, and Piran 1992; Piran 1994) and
failed supernovae, since in them the burst rate would be expected to be
proportional to the amount of blue light (Paczynski 1992).
Thus the lack of bright optical counterparts strongly favors the Galactic hypothesis.