Lick northern proper motion program. II - Solar motion and Galactic rotation

The Lick Northern Proper Motion (NPM) program has been described in Paper I. The NPM reductions for absolute proper motions and positions have been completed for 617 NPM fields, almost completely covering the sky more than ≡10° from the galactic plane between declinations -3° and +68°. To test the accuracy of the NPM proper motions, and to begin their use in galactic structure studies, the author has done solutions for galactic rotation and solar motion. He finds: (1) A = +11.31±1.06 and B = -13.91±0.92 km s-1kpc-1, consistent with a nearly flat galactic-rotation curve with a local circular velocity near 200 km s-1; (2) solar apex locations near the standard apex for low galactic latitudes, but trending strongly toward the direction of galactic rotation for high galactic latitudes; (3) external error estimates for the Lick proper motions: 0arcsec.2 century-1 for the absolute zero point in a typical NPM field, and 0arcsec.06±0arcsec.02 century-1 for the overall systematic zero-point error.