Observations of Binary Stars with the Differential Speckle Survey Instrument. VII. Measures from 2010 September to 2012 February at the WIYN Telescope

We report on speckle observations of binary stars carried out at the WIYN Telescope over the period from September 2010 through February 2012, providing relative astrometry for 2521 observations of 883 objects, 856 of which are double stars and 27 of which are triples. The separations measured span a range of 0.01 to 1.75 arc seconds. Wavelengths of 562 nm, 692 nm, and 880 nm were used, and differential photometry at one or more of these wavelengths is presented in most cases. Sixty-six components were resolved for the first time. We also estimate detection limits at 0.2 and 1.0 arc seconds for high-quality observations in cases where no companion was seen, a total of 176 additional objects. Detection limits vary based on observing conditions and signal-to-noise ratio, but are approximately 4 magnitudes at 0.2 arc seconds and 6 magnitudes at 1.0 arc seconds on average. Analyzing the measurement precision of the data set, we find that the individual separations obtained have linear measurement uncertainties of approximately 2 mas, and photometry is uncertain to approximately 0.1 magnitudes in general. This work provides fundamental, well-calibrated data for future orbit and mass determinations, and we present three first orbits and total mass estimates of nearby K-dwarf systems as examples of this potential.