The Washington Double Star Catalog (WDS) maintained by the United States Naval Observatory is the world's principal database of astrometric double and multiple star information. 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 154005 systems based on 1999750 means as of Wed Mar 31 09:34:46 EDT 2021 .
As can be seen in the figure below, the WDS and the other catalogs we
maintain are being added at a prodigious rate. A great deal of this work is
coming from data mining, especially of DR2 from Gaia. While this can be
useful, it is always there to be mined and based on some private discussions
it is possible that the best and final Gaia astrometric solution will not be
producted until DR4 or later.
As a result, we have generated a lists of pairs which need to be observed. This can be regenerated each time there is a major addition to the WDS, These lists include pairs which either are unconfirmed or pairs which have not been measured in many years ("many" set arbitrarily at 20 years). In the initial formulation two lists would be generated:
For these neglected pairs, even a non-detection can be useful if your
observing capability is much greater than the parameters of the pair in
question. For the neglected pairs where date - last is a very large
number, the pair may be lost or miscataloged, and it may involve detective
work or the perusal of old articles. This type of investigative work may
be found especially appealing.
The Washington Double Star Supplemental Catalog (WDSS) is a database intended for large, faint duplicity surveys and contains 890980 unique (not in the WDS) systems based on 5417182 unique (not in WDS) measures. It is expected to grow significantly as future data releases from Gaia, PanStarrs, etc. lead to ever-larger-scale duplicity surveys.
If the WDS and associated databases were helpful for your research work, the following acknowledgement would be appreciated:
``This research has made use of the Washington Double Star Catalog maintained at the U.S. Naval Observatory.''
A notification of references to relevant papers is appreciated.