The VISTA Variables in the Via Lactea survey: A first glance on stellar
  variability
  VISTA Variables in the Via Lactea (VVV) is an ESO public near-infrared
variability survey of the Galactic bulge and an adjacent area of the southern
mid-plane. It will produce a deep atlas in the ZYJHKs filters, and a Ks-band
time-series database of ~10^9 point sources, among which >~10^6 are expected to
be variable. One of VVV's immediate scientific goals is to provide accurate
light curves of primary distance indicators, such as RR Lyrae stars, and
utilize these data to produce a 3-D map of the surveyed area and, ultimately,
trace the structure of the inner Galaxy. We give, based on the first ~1.5 years
of the 5-yr-long survey, an early assessment on the basic properties and the
overall quality of the VVV photometric time-series, and use these data to put
an estimate of the fraction of variable stellar sources.
