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VIRAC2: NIR astrometry and time series photometry for 500M+ stars from the VVV and VVVX surveys
Journal
Monthly Notices of the Royal Astronomical Society
Date Issued
2024-12-20
Author(s)
Leigh C Smith
Philip W Lucas
Sergey E Koposov
Carlos Gonzalez-Fernandez
Javier Alonso-García
Dante Minniti
Jason L Sanders
Luigi R Bedin
Vasily Belokurov
N Wyn Evans
Maren Hempel
Valentin D Ivanov
Radostin G Kurtev
Roberto K Saito
Abstract
<jats:title>ABSTRACT</jats:title>
<jats:p>We present VIRAC2, a catalogue of positions, proper motions, parallaxes and Z, Y, J, H, and $K_s$ near-infrared photometric time series of 545 346 537 unique stars. The catalogue is based on a point spread function fitting reduction of nearly a decade of VISTA VVV and VVVX images, which cover $560~{\rm deg}^2$ of the Southern Galactic plane and bulge. The catalogue is complete at the $\gt 90$ per cent level for $11\lt K_s~{\rm mag}\lt 16$ sources, but extends to $K_s\approx {}17.5$ mag in most fields. Astrometric performance for $11\lt K_s~{\rm mag}\lt 14$ sources is typically $\approx {}0.37~{\rm mas~yr}^{-1}$ per dimension for proper motion, and $1~{\rm mas}$ for parallax. At $K_s=16$ the equivalent values are around $1.5~{\rm mas~yr}^{-1}$ and $5~{\rm mas}$. These uncertainties are validated against Gaia DR3 and Hubble Space Telescope astrometry. The complete catalogues are available via the ESO archive. We perform an initial search of the catalogue for nearby ultracool dwarf candidates. In total, we find 26 new sources whose parallaxes place them within 50 parsecs of the Sun. Among them we find two high-confidence T dwarfs and a number of other sources that appear to lie close to the L/T transition.</jats:p>
<jats:p>We present VIRAC2, a catalogue of positions, proper motions, parallaxes and Z, Y, J, H, and $K_s$ near-infrared photometric time series of 545 346 537 unique stars. The catalogue is based on a point spread function fitting reduction of nearly a decade of VISTA VVV and VVVX images, which cover $560~{\rm deg}^2$ of the Southern Galactic plane and bulge. The catalogue is complete at the $\gt 90$ per cent level for $11\lt K_s~{\rm mag}\lt 16$ sources, but extends to $K_s\approx {}17.5$ mag in most fields. Astrometric performance for $11\lt K_s~{\rm mag}\lt 14$ sources is typically $\approx {}0.37~{\rm mas~yr}^{-1}$ per dimension for proper motion, and $1~{\rm mas}$ for parallax. At $K_s=16$ the equivalent values are around $1.5~{\rm mas~yr}^{-1}$ and $5~{\rm mas}$. These uncertainties are validated against Gaia DR3 and Hubble Space Telescope astrometry. The complete catalogues are available via the ESO archive. We perform an initial search of the catalogue for nearby ultracool dwarf candidates. In total, we find 26 new sources whose parallaxes place them within 50 parsecs of the Sun. Among them we find two high-confidence T dwarfs and a number of other sources that appear to lie close to the L/T transition.</jats:p>