USNO-B1.0: All-Sky Star Catalog from Photographic Plates, 1949-2002

1,045,175,762 celestial objects are cataloged in this all-sky dataset derived from nearly 7,500 photographic plates. The United States Naval Observatory created USNO-B1.0 to improve upon earlier catalogs by including objects detected in the same band at two epochs and those with significant proper motions. Data originates from five complete coverages of the northern sky and four of the southern sky taken between 1949 and 2002.

Use Cases

• Train star/galaxy classification models based on the 85% accuracy for distinguishing stellar from non-stellar objects.
• Analyze stellar proper motions using multi-epoch detections from surveys spanning over 50 years.
• Calibrate or validate other astronomical surveys using the catalog's estimated 0.2 arcsec positional accuracy.
• Study the completeness of celestial object detection down to a magnitude of V=21.

Strengths

• Massive scale with over 1 billion cataloged objects.
• Multi-epoch coverage from surveys conducted between 1949 and 2002.
• High estimated positional accuracy of 0.2 arcsec.
• Designed to be more complete than its predecessor by including objects detected in the same band at two epochs.

Limitations

• Objects with large proper motions and extreme colors may still be omitted from the catalog.
• Column-level documentation is absent; field semantics must be inferred after download.
• Photographic magnitude accuracies are estimated at 0.3 mag, which may limit precision for some analyses.

Provenance

Source

United States Naval Observatory, as described in Monet et al. (2003).

Collection Method

Derived from digitizing scans of almost 7,500 photographic plates from various sky surveys.

Time Range

1949 to 2002

Freshness

Last updated 2026-03-13 16:34:11.777062; freshness should be verified.

Geography

All-sky coverage (northern and southern hemispheres)