  The Lick Northern Proper Motion (NPM) program, a two-epoch (1947-1988)
photographic survey of the northern two-thirds of the sky (Dec. > -23 deg), has
measured absolute proper motions, on an inertial system defined by distant
galaxies, for 380,000 stars from 8 <B < 18. The 1993 NPM1 Catalog contains
148,940 stars in 899 fields outside the Milky Way's zone of avoidance. The 2003
NPM2 Catalog contains 232,062 stars in the remaining 347 NPM fields near the
plane of the Milky Way. This paper describes the NPM2 star selection, plate
measurements, astrometric and photometric data reductions, and catalog
compilation. The NPM2 Catalog contains 120,000 faint (B > 14) anonymous stars
for astrometry and galactic studies, 92,000 bright (B < 14) positional
reference stars, and 35,000 special stars chosen for astrophysical interest.
The NPM2 proper motions are on the ICRS system, via Tycho-2 stars, to an
accuracy of 0.5 mas/yr in each field. RMS proper motion precision is 6 mas/yr.
Positional errors average 80 mas at the mean plate epoch 1968, and 200 mas at
the NPM2 catalog epoch 2000. NPM2 photographic photometry errors average 0.18
mag in B, and 0.20 mag in B-V. The NPM2 Catalog and the updated (to J2000) NPM1
Catalog are available at the CDS Strasbourg data center and on the NPM WWW site
(http://www.ucolick.org/~npm). The NPM2 Catalog completes the Lick Northern
Proper Motion program after a half-century of work by three generations of Lick
Observatory astronomers. The NPM Catalogs will serve as a database for research
in galactic structure, stellar kinematics, and astrometry.
