SIMBAD references

The ESA Hipparcos satellite made measurements of over 12,000 double stars and discovered 3406 new systems. In addition to these, 4706 entries in the Hipparcos Catalogue correspond to double star solutions that did not provide the classical parameters of separation and position angle (ρ,θ) but were the so-called problem stars, flagged ``G'', ``O'', ``V'', or ``X'' (field H59 of the main catalog). An additional subset of 6981 entries were treated as single objects but classified by Hipparcos as ``suspected nonsingle'' (flag ``S'' in field H61), thus yielding a total of 11,687 ``problem stars.'' Of the many ground-based techniques for the study of double stars, probably the one with the greatest potential for exploration of these new and problem Hipparcos binaries is speckle interferometry.
Result. are presented from an inspection of 848 new and problem Hipparcos binaries, using both archival and new speckle observations obtained with the USNO and CHARA speckle cameras.