ATLAS All-Sky Stellar Reference Catalog: One Billion Stars to Magnitude 19

ATLAS Refcat2 is a reference catalog of approximately one billion stars assembled to calibrate astrometry and photometry for the Asteroid Terrestrial-impact Last Alert System (ATLAS). The catalog aims for at least 99% completeness to magnitude less than 19, incorporating data from Gaia DR2, Pan-STARRS DR1, SkyMapper DR1, and other sources. It is provided by the National Aeronautics and Space Administration and was last updated in March 2026.

Use Cases

• Calibrate photometric accuracy for wide-field astronomical exposures based on the all-sky reference catalog.
• Perform astrometric corrections using Gaia DR2 sourced positions mentioned in the description.
• Study stellar variability with a baseline catalog where systematic errors are reported to be no larger than 5 millimag RMS.
• Assess completeness of stellar populations in different sky regions based on the stated 99% completeness goal to magnitude 19.

Strengths

• Catalog contains approximately one billion stars, providing a large-scale reference.
• Aims for at least 99% completeness to magnitude less than 19, including bright stars.
• Systematic errors are reported to be no larger than 5 millimag RMS in most areas.

Limitations

• Photometric errors can be as large as 20 millimag in small patches near the galactic plane.
• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Assembled from multiple astronomical survey data sources including Gaia DR2, Pan-STARRS DR1, and SkyMapper DR1.

Time Range

null

Freshness

Last updated 2026-03-13 18:17:36.041488; freshness should be verified.

Geography

All-sky coverage.