The VISTA Variables in the Via Lactea survey: A first glance on stellar variability

TL;DR

The VVV survey provides near-infrared variability data of the Galactic bulge, enabling detailed studies of stellar variability and Galactic structure, with initial results from the first 1.5 years of data.

Contribution

This paper presents the first assessment of the VVV survey's photometric quality and variability fraction based on early data, advancing near-infrared stellar variability studies.

Findings

Estimated fraction of variable stars in the survey

Assessment of photometric data quality

Initial insights into stellar variability in the Galactic bulge

Abstract

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.