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W.I. Hartkopf, B.D. Mason (U.S. Naval Observatory)
The Washington Double Star program at the U.S. Naval Observatory has seen considerable activity in the last several years. Some examples:
* Over 15,000 observations from its speckle interferometry program have been published or are in preparation, making it the most productive speckle observing effort now in operation.
* Nearly 36,000 measures of wider binaries have been gleaned from the 144 transit circle and astrograph catalogs which were incorporated in the production of the Tycho-2 astrometry catalog.
* As a result of these and other efforts, the WDS database, which traces its roots back to Burnham's 1906 catalog, now consists of 84,300 systems based on 549,444 mean positions, an increase of 8% in systems and 22% in mean positions during the past five years alone.
* A new catalog of visual binary star orbits has recently been posted to the web. The Fifth Catalog of Orbits of Visual Binary Stars is nearly 60% larger than its immediate predecessor, the Worley & Heintz (1983) Fourth Catalog. An objective grading scheme was developed using all published measures, whose results are consistent with the more subjective grading methods of previous catalogs. Unlike previous catalogs, however, the Fifth Catalog also provides ephemerides for all systems, as well as figures which include all measures contained in the WDS database.
All USNO double star catalogs are continuously maintained and their data made available either on the web or via our data request software. A new CD-ROM has also been produced, containing the WDS summary catalog, the Fifth Orbit Catalog, the Third Interferometric Catalog, and numerous ancillary files; all catalogs are current to 2001.0. Copies of this CD-ROM are available free of charge from the authors.
We gratefully acknowledge four decades of continuous support for double star program by the U.S. Naval Observatory, Washington, DC.