We present the first results from an ongoing survey for multiplicity among the bright stars using the Navy Precision Optical Interferometer ( NPOI ) .
We first present a summary of NPOI observations of known multiple systems , including the first detection of the companion of \beta Scuti with precise relative astrometry , to illustrate the instrument ’ s detection sensitivity for binaries at magnitude differences \Delta m \lessapprox 3 over the range of angular separation 3 - 860 milliarcseconds ( mas ) .
A limiting \Delta m _ { 700 } \sim 3.5 is likely for binaries where the component spectral types differ by less than two .
Model fits to these data show good agreement with published orbits , and we additionally present a new orbit solution for one of these stars , \sigma Her .
We then discuss early results of the survey of bright stars at \delta \geq -20 \arcdeg .
This survey , which complements previous surveys of the bright stars by speckle interferometry , initially emphasizes bright stars of spectral types F0 through K2 .
We report observations of 41 stars of apparent visual magnitude m _ { V } \leq 4.30 , all having been observed on multiple nights .
Analysis of these data produces fitted angular separations , position angles , and component magnitude differences for six previously known visual binaries .
Three additional systems were examined as possible binaries , but no conclusive detection could be made .
No evidence of close stellar companions within our detection limit of \Delta m \approx 3 was found for the remaining 32 stars observed ; however , uniform-disk angular diameters are reported for 11 of the resolved stars in this last group .