Speckle observations with PISCO in Merate: XI. Astrometric measurements of visual binaries in 2010

We present relative astrometric measurements of visual binaries made in 2010 with the Pupil Interferometry Speckle camera and COronagraph (PISCO) on the 102 cm Zeiss telescope of the Brera Astronomical Observatory, in Merate. Our observing list contains orbital couples as well as binaries whose motion is still uncertain. We obtained new 207 measurements of 191 objects, with angular separations in the range 0.2-4.7 arcsec and an average accuracy of 0.01 arcsec. The mean error on the position angles is 0°.6. Most of the position angles were determined without the usual 180° ambiguity with the application of triple-correlation techniques and/or by inspection of the long integration files. We also present revised orbits for ADS 5469, 8128, 8239 and 10345, and new orbits for ADS 10850 and 11170, partly derived from those observations, and infer estimated values for the masses of those systems that are compatible with the spectral types.