  We report the discovery of a super-Earth mass planet in the microlensing
event MOA-2012-BLG-505. This event has the second shortest event timescale of
$t_{\rm E}=10 \pm 1$ days where the observed data show evidence of planetary
companion. Our 15 minute high cadence survey observation schedule revealed the
short subtle planetary signature. The system shows the well known close/wide
degeneracy. The planet/host-star mass ratio is $q =2.1 \times 10^{-4}$ and the
projected separation normalized by the Einstein radius is s = 1.1 or 0.9 for
the wide and close solutions, respectively. We estimate the physical parameters
of the system by using a Bayesian analysis and find that the lens consists of a
super-Earth with a mass of $6.7^{+10.7}_{-3.6}M_{\oplus}$ orbiting around a
brown-dwarf or late M-dwarf host with a mass of $0.10^{+0.16}_{-0.05}M_{\odot}$
with a projected star-planet separation of $0.9^{+0.3}_{-0.2}$AU. The system is
at a distance of $7.2 \pm 1.1$ kpc, i.e., it is likely to be in the Galactic
bulge. The small angular Einstein radius ($\theta_{\rm E}=0.12 \pm 0.02$ mas)
and short event timescale are typical for a low-mass lens in the Galactic
bulge. Such low-mass planetary systems in the Bulge are rare because the
detection efficiency of planets in short microlensing events is relatively low.
This discovery may suggest that such low mass planetary systems are abundant in
the Bulge and currently on-going high cadence survey programs will detect more
such events and may reveal an abundance of such planetary systems.
