  We present the results of a detailed, systematic stellar evolution study of
binary mergers for blue supergiant (BSG) progenitors of Type II supernovae. In
particular, these are the first evolutionary models that can simultaneously
reproduce nearly all observational aspects of the progenitor of SN 1987A,
$\text{Sk}-69\,^{\circ}202$, such as its position in the HR diagram, the
enrichment of helium and nitrogen in the triple-ring nebula, and its lifetime
before its explosion. The merger model, based on the one proposed by
Podsiadlowski 1992 et al. and Podsiadlowski 2007 et al., consists of a main
sequence secondary star that dissolves completely in the common envelope of the
primary red supergiant at the end of their merger. We empirically explore a
large initial parameter space, such as primary masses ($15\,\text{M}_{\odot}$,
$16\,\text{M}_{\odot}$, and $17\,\text{M}_{\odot}$), secondary masses
($2\,\text{M}_{\odot}$, $3\,\text{M}_{\odot}$, ..., $8\,\text{M}_{\odot}$) and
different depths up to which the secondary penetrates the He core of the
primary during the merger. The evolution of the merged star is continued until
just before iron-core collapse and the surface properties of the 84
pre-supernova models ($16\,\text{M}_{\odot}-23\,\mathrm{M}_{\odot}$) computed
have been made available in this work. Within the parameter space studied, the
majority of the pre-supernova models are compact, hot BSGs with effective
temperature $>12\,\text{kK}$ and radii of
$30\,\text{R}_{\odot}-70\,\mathrm{R}_{\odot}$ of which six match nearly all the
observational properties of $\text{Sk}-69\,^{\circ}202$.
