The USNO-B1.0 is a catalog that presents positions, proper motions,
magnitudes in various optical passbands, and star/galaxy estimators
for 1,045,913,669 objects derived from 3,648,832,040 separate
observations. The data were taken from scans of 7,435 Schmidt plates
taken from various sky surveys during the last 50 years.
The catalog is expected to be complete down to V=21; the estimated
accuracies are 0.2arcsec for the positions at J2000, 0.3mag in up to 5
colors, and 85% accuracy for distinguishing stars from non-stellar
objects.
