Large-Angle Astrometry at the Navy Prototype Optical Interferometer (NPOI)

We report progress and plans for the astrometric cataloging efforts at the NPOI. The NPOI has been conducting a regular program of large-angle astrometric observations since 2005 towards an initial goal of producing a catalog of at least 100 bright (V < 5) stars with positions accurate to < 16 milliarcseconds (mas). To date, precisions of < 16 mas have been demonstrated for 60 stars (median precisions of 7 mas in RA and Dec). We are also conducting an independent relative astrometry program using telescopes at NOFS to assess the accuracy of the NPOI observations by referencing each of the relatively bright NPOI targets to nearby USNO Astrograph Catalog (UCAC) stars. We also report on plans to utilize the four 1.8 m telescopes obtained from the Keck Interferometer project to enhance the NPOI astrometric cataloging efforts towards much fainter and numerous targets and for observations of selected targets in support of risk-reduction strategies for the J-MAPS program. The NPOI is a joint project of the U.S. Naval Observatory and the Naval Research Laboratory, in cooperation with Lowell Observatory, and is funded by the Oceanographer of the Navy and the Office of Naval Research.