Previous
abstract 
Next
abstract
Session 108 - The Galactic Stellar Disk & Halo.
Display session, Saturday, January 10
Exhibit Hall,
As part of the Minnesota Automated Plate Scanner project, we are repeating the proper motion survey for which the machine was originally built. We have scanned the Palomar Schmidt red plates taken by Willem Luyten in the 1960's with copies of the POSS I red plates. Epoch difference varies from field to field to field but is typically in the range of 11-15 years. With the upgrade to the APS and improvements in computing since Luyten's original survey, we expect to measure the relative displacements of objects between the first and second epoch plates to the APS limiting accuracy, about 1 \mum (0\d"07). This corresponds to a relative proper motion precision of 0\d"006 year^-1 for a 12-year baseline. Objects classified as galaxies in the APS catalog of the POSS I will be measured along with the stars and used to set the absolute proper motion zero-point. The survey will cover the 664 fields with |b|>20^\circ, and we estimate the proper motion catalog to contain about 6.6\times10^7 stars brighter than E magnitude \sim20, about half of which should have individually measurable (1\sigma) motions; those that do not will still be statistically useful. The proper motion catalog will be by far the largest such catalog in existence. The APS Proper Motion Database will join the APS Object and Image databases online and will be available to the astronomical community. The database will be useful for placing both kinematic and structural constraints on Galactic models, as well as the search for Pop II white dwarfs, lower main sequence stars, brown dwarfs, common motion pairs, moving groups, etc. This paper describes the strategy for deriving the proper motions and current progress.
