PPM: Positions and Proper Motions Catalog for 378,910 Stars

The PPM database combines the PPM North and PPM South catalogs, a Bright Stars Supplement, and a 90,000 Stars Supplement. It provides positions and proper motions for 378,910 stars, effectively replacing older catalogs like SAO with improved precision on the J2000/FK5 coordinate system. The dataset was updated by the HEASARC in October 1999 based on ADC/CDS catalog data and is provided by the National Aeronautics and Space Administration.

Use Cases

• Calculate stellar trajectories based on proper motion data.
• Cross-match celestial objects using precise J2000/FK5 coordinate system positions.
• Analyze star density and positional accuracy differences between northern and southern hemispheres.
• Supplement other star catalogs using the included Bright Stars and 90,000 Stars supplements.

Strengths

• Covers 378,910 stars (181,731 north, 197,179 south) with positions and proper motions.
• Offers improved precision over the SAO Catalogue, with typical rms errors of 0.27 arcsec in position and 0.42 arcsec/century in proper motion for the northern hemisphere.
• Includes supplements to ensure completeness down to V=7.5 magnitude and add approximately 100,000 CPC-2 stars.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown for the full combined database, which may limit suitability assessment.
• Last updated 2026-03-13 17:09:23.514685; freshness should be verified for current applications.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Combination of multiple catalogs (PPM North, PPM South, Bright Stars Supplement, 90,000 Stars Supplement) derived from position measurements including the Astrographic Catalogue.

Time Range

Positions are at epoch 1990.

Freshness

Last updated 2026-03-13 17:09:23.514685.

Geography

Celestial coverage: stars north and south of -2.5 degrees declination.