Combining visual and spectroscopic orbits of binary stars leads to a determination of the full 3D orbit , individual masses , and distance to the system .
We present a full analysis of the evolved binary system \delta Delphini using astrometric data from the MIRC and PAVO instruments on the CHARA long-baseline interferometer , 97 new spectra from the Fairborn Observatory , and 87 unpublished spectra from Lick Observatory .
We determine the full set of orbital elements for \delta Del , along with masses of 1.78 \pm 0.07 M _ { \odot } and 1.62 \pm 0.07 M _ { \odot } for each component , and a distance of 63.61 \pm 0.89 pc .
These results are important in two contexts : for testing stellar evolution models and defining the detection capabilities for future planet searches .
We find that the evolutionary state of this system is puzzling , as our measured flux ratios , radii , and masses imply a \sim 200 Myr age difference between the components using standard stellar evolution models .
Possible explanations for this age discrepancy include mass transfer scenarios with a now ejected tertiary companion .
For individual measurements taken over a span of 2 years we achieve < 10 \mu -arcsecond precision on differential position with 10-minute observations .
The high precision of our astrometric orbit suggests that exoplanet detection capabilities are within reach of MIRC at CHARA .
We compute exoplanet detection limits around \delta Del , and conclude that if this precision is extended to wider systems we should be able to detect most exoplanets > 2 M _ { J } on orbits > 0.75 AU around individual components of hot binary stars via differential astrometry .