New orbits based on speckle interferometry at SOAR

Orbits of 55 visual binary stars are computed using recent speckle interferometry data from the SOAR telescope: 33 first-time orbits and 22 revisions of previous orbit calculations. The orbital periods range from 1.4 to 370 years, the quality of orbits ranges from definitive to preliminary and tentative. Most binaries consist of low-mass dwarfs and have short periods (median period 31 years). The dynamical parallaxes and masses are evaluated and compared to the Hipparcos parallaxes. Using differential speckle photometry, binary components are placed on the color-magnitude diagram.