An Intriguing Globular Cluster in the Galactic Bulge from the VVV Survey
  Recent near-IR Surveys have discovered a number of new bulge globular cluster
(GC) candidates that need to be further investigated. Our main objective is to
use public data from the Gaia Mission, VVV, 2MASS and WISE in order to measure
the physical parameters of Minni48, a new candidate GC located in the inner
bulge of the Galaxy at l=359.35 deg, b=2.79 deg. Even though there is a bright
foreground star contaminating the field, the cluster appears quite bright in
near- and mid-IR images. We obtain deep decontaminated optical and near-IR
colour-magnitude diagrams (CMDs) for this cluster. The heliocentric cluster
distance is determined from the red clump (RC) and the red giant branch (RGB)
tip magnitudes in the near-IR CMD, while the cluster metallicity is estimated
from the RGB slope and the fit to theoretical isochrones. The GC size is found
to be r = 6' +/- 1', while reddening and extinction values are E(J-Ks)=0.60 +/-
0.05 mag, A_G=3.23 +/- 0.10 mag, A_Ks=0.45 +/- 0.05 mag. The resulting mean
Gaia proper motions are PMRA=-3.5 +/- 0.5 mas/yr, PMDEC=-6.0 +/- 0.5 mas/yr.
The IR magnitude of the RC yields an accurate distance modulus estimate of
(m-M)_0=14.61 mag, equivalent to a distance D=8.4 +/- 1.0 kpc. This is
consistent with the optical distance estimate: (m-M)_0=14.67 mag, D=8.6 +/- 1.0
kpc, and with the RGB tip distance: (m-M)_0=14.45 mag, D=7.8 +/- 1.0 kpc. The
derived metallicity is [Fe/H]=-0.20 +/- 0.30 dex. A good fit to the PARSEC
stellar isochrones is obtained in all CMDs using Age = 10 +/- 2 Gyr. The total
absolute magnitude of this GC is estimated to be M_Ks= -9.04 +/- 0.66 mag.
Based on its position, kinematics, metallicity and age, we conclude that
Minni48 is a genuine GC, similar to other well known metal-rich bulge GCs. It
is located at a projected Galactocentric angular distance of 2.9 deg,
equivalent to 0.4 kpc, being one of the closest GCs to the Galactic centre.
