  In our search for gamma-ray emission from Be X-ray binaries from analysis of
the data obtained with the Large Area Telescope (LAT) on board the Fermi
Gamma-Ray Space Telescope, we find likely detection of GRO J1008-57. The binary
has an orbital period of 249.48 days, and it is only significantly detected in
its orbital phase 0.8--0.9 (>4 sigma). Further light curve analysis indicates
that the detection is probably largely due to an emitting event in one orbital
cycle around year 2012--2013, following a giant X-ray outburst of the source.
This property of having occasional gamma-ray emitting events is similar to that
seen in another high-mass X-ray binary 4U 1036-56. However, models considering
possible gamma-ray emission from an accreting neutron star have difficulty in
explaining the observed 10^{34} erg s^{-1} luminosity of the source, unless the
distance was largely over-estimated. Further observational studies are
required, in order to more clearly establish the high-energy emission
properties of GRO J1008-57 or similar high-mass X-ray binaries and find clues
for understanding how gamma-ray emission is produced from them.

High Energy Astrophysical Phenomena