These files are no longer updated. This is an archival website for the
1996.0 edition of the Washington Double Star Catalog and 4th Orbit Catalog.
The last major update to this site was 9 October 1998 by Geoffrey Douglass.
The Washington Double Star Catalog (WDS)
maintained by the USNO is the principal database of astrometric double and
multiple star data. The WDS Catalog contains positions (J2000), discoverer
designations, epochs, position angles, separations, magnitudes, spectral types,
proper motions, and, when available, Durchmusterung numbers and Notes for the
components of 78,100 systems based on 451,546 means. The present WDS (1996.0) is
a major revision of the 1984.0 version. More precise magnitudes (photographic
and photoelectric), and MK spectral types have been included where available.
The WDS Notes have been extensively revised to include information on orbital
motion and multiplicity (including astrometric, photometric, and spectroscopic),
variability, composite spectra, etc. For pairs with orbits, the period,
semi-major axis, and direction of motion are given. The stars with
Durchmusterung numbers have been individually compared with the SIMBAD database.
All stars with Durchmusterung numbers have also been matched with the ACRS, PPM,
IRS, and FK5 astrometric catalogs in order to provide more accurate positions
and proper motions. Since new data are continually being added to the database,
the WDS is updated on a regular basis. Upon request, data from the Observation
Catalog for individual objects are supplied to users world-wide
(eqb@draco.usno.navy.mil).
You may request
a reasonable amount of information from the double star catalog by e-mail.
Please provide comments on format of WDS, missed references, or any other
items of interest to you on our Comment form
The Orbit Star Catalog contains the orbital elements for systems whose orbits
have been determined along with ephemerides that in each case span the period
1990 through 2009. In addition, special requests for ephemerides of orbit stars
can be met by the USNO.
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