ESO is pleased to announce the public release of the VVV Infrared Astrometric Catalogues (VIRAC) Version 2. The catalogues are based on data from the VISTA Variables in the Via Lactea (VVV) Survey and its extension, VVVX, and offer unprecedented precision in astrometric and depth.
Release of the VIRAC Version2 Catalogues from the VVV and VVVX Surveys
Published: 23 Dec 2024
The VIRAC2 catalogues include positional data, proper motions, parallaxes, and near-infrared time series for over 545 million stars across approximately 560 square degrees of the southern sky, using data from 2010 to 2019 in ZYJHKs bands. They use Gaia DR3 as an external astrometric reference catalogue, and hence astrometry is on an absolute reference frame, in contrast to VIRAC v1. A global photometric calibration algorithm has been adopted, using 2MASS as an external photometric reference catalogue, with an additional non-astrophysical noise reduction stage.
The catalogues reach magnitudes as faint as Ks ≈ 17.5, approximately 1 mag deeper than VIRACv1, and achieve proper motion uncertainties as low as 0.37 mas/yr for bright sources. Parallax measurements are available for all stars observed in at least ten epochs.
The release includes five tables:
- VVVX_VIRAC_V2_SOURCES
- VVVX_VIRAC_V2_LC
- VVVX_VIRAC_V2_REJECTED_SOURCES
- VVVX_VIRAC_V2_REJECTED_LC
- VVVX_VIRAC_V2_OBS.
The source tables I and III contain the aggregate source data (e.g. positions, proper motions, mean photometry), tables II and IV are the time series data (photometric and astrometric), and table (v) contains observation-related information (e.g. image filename, seeing). The content has been split into main and rejected selections. The raw catalogue contained junk rows for a variety of reasons (e.g. duplicates, erroneous detections in the wings of the PSFs of bright stars, etc.), and these were separated into the rejected tables which are included since some interesting sources (e.g. photometric transients) can have been flagged as ‘rejected’.
Together with the catalogues, complementary data, including over 24,000 pawprint images, source tables, and confidence maps, are also provided. More information is available in the release documentation.
Catalogues can be queried via the Catalog Query Interface, or programmatically, here some query examples:
Select all source table data of high pm star candidates
Select all source table data of nearby star candidates
Select the time series of VVV-WIT-08
Data can be downloaded also via the ESO Archive Science Portal.