摘要：The results of 3989 intensified CCD observations of double stars, made with the 26-inch refractor of the U.S. Naval Observatory, are presented. Each observation of a system represents a combination of over 2000 short-exposure images. These observations are averaged into 1911 mean relative positions and range in separation from 0 289 to 128 638, with a median separation of 8 669. Four orbits are improved. This is the 23rd in this series of papers and covers the period 2017 January 4 through 2017 September 13.
