We present an updated spectroscopic orbit and a new visual orbit for the double-lined spectroscopic binary \sigma ^ { 2 } Coronae Borealis based on radial velocity measurements at the Oak Ridge Observatory in Harvard , Massachusetts and interferometric visibility measurements at the CHARA Array on Mount Wilson . \sigma ^ { 2 } CrB is composed of two Sun-like stars of roughly equal mass in a circularized orbit with a period of 1.14 days .
The long baselines of the CHARA Array have allowed us to resolve the visual orbit for this pair , the shortest period binary yet resolved interferometrically , enabling us to determine component masses of 1.137 \pm 0.037 M _ { \odot } and 1.090 \pm 0.036 M _ { \odot } .
We have also estimated absolute V -band magnitudes of M _ { V } { ( primary ) } = 4.35 \pm 0.02 and M _ { V } { ( secondary ) } = 4.74 \pm 0.02 .
A comparison with stellar evolution models indicates a relatively young age of 1–3 Gyr , consistent with the high Li abundance measured previously .
This pair is the central component of a quintuple system , along with another similar-mass star , \sigma ^ { 1 } CrB , in a \sim 730-year visual orbit , and a distant M-dwarf binary , \sigma CrB C , at a projected separation of \sim 10 \arcmin .
We also present differential proper motion evidence to show that components C & D ( ADS 9979C & D ) listed for this system in the Washington Double Star Catalog are optical alignments that are not gravitationally bound to the \sigma CrB system .