ACRS: Astrographic Catalog of Reference Stars for Celestial Reference

A 1990s-era high-density catalog of stellar positions and proper motions compiled to provide a consistent celestial reference system. The Smithsonian Astrophysical Observatory and U.S. Naval Observatory compiled 1,643,783 input positions from over a dozen source catalogs, reducing them to the FK4 system. It is divided into two parts, with Part 1 containing 78% of stars with more reliable positions and proper motions.

Use Cases

• Reducing historical photographic plate data based on the catalog's original purpose for the Astrographic Catalogue plates.
• Analyzing stellar proper motion accuracy based on the reported mean errors of +/-0.47 arcsec per century.
• Comparing celestial reference systems based on the catalog's rigorous reduction to the FK4 system.
• Selecting reference stars for telescope pointing or calibration based on the high-density coverage of the sky.

Strengths

• Contains 1,643,783 input positions, indicating a high-density catalog.
• Part 1 stars have mean proper motion errors of +/-0.47 and +/-0.46 arcsec per century in right ascension and declination, providing a quantitative accuracy measure.
• Compiled from over a dozen source catalogs, including CPC2, AGK3, and meridian circle catalogs, suggesting a broad observational base.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data may reflect temporal bias inherent to its 1990s compilation and reliance on historical photographic surveys.

Provenance

Source

U.S. Naval Observatory, compiled from multiple astronomical catalogs.

Collection Method

Positions from source catalogs were matched, reduced to the FK4 system, and combined.

Time Range

Based on source catalogs referenced, likely spans much of the 20th century.

Freshness

Last updated 2026-03-13 16:59:27.174461; freshness should be verified.

Geography

Covers the entire sky, with specific mention of southern hemisphere coverage from CPC2.