A deep proper motion catalog within the Sloan digital sky survey footprint

A new proper motion catalog is presented, combining the Sloan Digital Sky Survey (SDSS) with second epoch observations in the r band within a portion of the SDSS imaging footprint. The new observations were obtained with the 90prime camera on the Steward Observatory Bok 90 inch telescope, and the Array Camera on the U.S. Naval Observatory, Flagstaff Station, 1.3 m telescope. The catalog covers 1098 square degrees to r = 22.0, an additional 1521 square degrees to r = 20.9, plus a further 488 square degrees of lesser quality data. Statistical errors in the proper motions range from 5 mas year⁻¹ at the bright end to 15 mas year⁻¹ at the faint end, for a typical epoch difference of six years. Systematic errors are estimated to be roughly 1 mas year⁻¹ for the Array Camera data, and as much as 2–4 mas year⁻¹ for the 90prime data (though typically less). The catalog also includes a second epoch of r band photometry.