We use deep multi-epoch near-IR images of the VISTA Variables in the Vía Láctea ( VVV ) Survey to search for RR Lyrae stars towards the Southern Galactic plane .
Here we report the discovery of a group of RR Lyrae stars close together in VVV tile d025 .
Inspection of the VVV images and PSF photometry reveals that most of these stars are likely to belong to a globular cluster , that matches the position of the previously known star cluster FSR 1716 .
The stellar density map of the field yields a > 100 sigma detection for this candidate globular cluster , that is centered at equatorial coordinates RA _ { J 2000 } = 16:10:30.0 , DEC _ { J 2000 } = - 53:44:56 ; and galactic coordinates l = 329.77812 , b = - 1.59227 .
The color-magnitude diagram of this object reveals a well populated red giant branch , with a prominent red clump at K _ { s } = 13.35 \pm 0.05 , and J - K _ { s } = 1.30 \pm 0.05 .
We present the cluster RR Lyrae positions , magnitudes , colors , periods and amplitudes .
The presence of RR Lyrae indicates an old globular cluster , with age > 10 Gyr .
We classify this object as an Oosterhoff type I globular cluster , based on the mean period of its RR Lyrae type ab , < P > = 0.540 days , and argue that this is a relatively metal-poor cluster with [ Fe / H ] = -1.5 \pm 0.4 dex .
The mean extinction and reddening for this cluster are A _ { K _ { s } } = 0.38 \pm 0.02 , and E ( J - K _ { s } ) = 0.72 \pm 0.02 mag , respectively , as measured from the RR Lyrae colors and the near-IR color-magnitude diagram .
We also measure the cluster distance using the RR Lyrae type ab stars .
The cluster mean distance modulus is ( m - M ) _ { 0 } = 14.38 \pm 0.03 mag , implying a distance D = 7.5 \pm 0.2 kpc , and a Galactocentric distance R _ { G } = 4.3 kpc .