Locating Double Stars in the UCAC with the WDS Catalog and CCD Parameters

Abstract

Abstract : Double star orbits are determined to aid navigation and communications, but are often compiled from limited observations. The identification of double stars in the USNO CCD Astrograph Catalog (UCAC) provides a means to discover new double stars and improve orbital information for known double stars. Several artifacts remained in the pixel data after the UCAC2 release, including the presence of a bright streak along the x-axis of bright stars resulting from a shutter problem, and the presence of cosmic ray events on individual CCD frames. Starting with a list of already identified potential double stars, these artifacts were detected and potential double stars were flagged for whether they were affected by either artifact. In addition, the Washington Double Star Catalog was matched with potential UCAC double stars. From these identifications, each potential double star was flagged for whether (1) they actually do not exist but were listed due to being on a streak, (2) they are cosmic rays instead, or (3) they are most likely double stars, verified with a Washington Double Star Catalog match if possible. Despite that matches were within 1-15 px of each other, coordinate accuracy could still be improved by using double orbital catalogs and proper motions from the UCAC. Most cosmic ray events and almost all bright streaks were detected successfully, providing a sortable list of double stars that can be used by astronomers to discover new double stars and improve currently known double stars' orbits.