SIMBAD references

The results of 2916 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 two thousand short-exposure images. These observations are averaged into 1584 mean relative positions and range in separation from 0.''54 to 98.''09, with a median separation of 11.''73. This is the 19th in this series of papers and covers the period 2012 January 5 through 2012 December 18. Also presented are 10 pairs that are reported for the first time, 17 pairs that appear to be lost, linear elements for 18 pairs, and orbital elements for 2 additional pairs.