  The helium-merger gamma-ray burst progenitor is produced by the rapid
accretion onto a compact remnant (neutron star or black hole) when it undergoes
a common envelope inspiral with its companion's helium core. This merger phase
produces a very distinct environment around these outbursts and recent
observations suggest that, in some cases, we are detecting the signatures of
the past merger in the GRB afterglow. These observations allow us, for the
first time, to study the specific features of the helium merger progenitor. In
this paper, we couple population synthesis calculations to our current
understanding of gamma-ray burst engines and common envelope evolution to make
observational predictions for the helium-merger gamma-ray burst population.
Many mergers do not produce GRB outbursts and we discuss the implications of
these mergers with the broader population of astrophysical transients.
