The pair were found to be adouble star byF. G. W. Struve in 1827 and given the catalogue identifier Σ 2173 (now STF 2173). Since then it has completed multiple orbits,[12] yieldingorbital elements showing aperiod of 46.3 years and aneccentricity of 0.17.[3] The two components have similar spectra that match astellar classification of G9IV-V.[3] They show almost no luminosity variation; one of the pair appears to vary by 0.002 in magnitude.[4] Both components have a slightly lower mass than the Sun: 96% and 95%, respectively.[6] The system is estimated to be 12.3 billion years old.[7]
^abcdefMalagnini, M. L.; Morossi, C. (November 1990). "Accurate absolute luminosities, effective temperatures, radii, masses and surface gravities for a selected sample of field stars".Astronomy and Astrophysics Supplement Series.85 (3):1015–1019.Bibcode:1990A&AS...85.1015M.
^abLockwood, G. W. (1998). Balasubramaniam, K. S.; Harvey, Jack; Rabin, D. (eds.). "Luminosity and Chromospheric Variations of Solar Analog Stars".Synoptic Solar Physics -- 18th NSO/Sacramento Peak Summer Workshop Held at Sunspot; New Mexico 8-12 September 1997. ASP Conference Series.140: 261.Bibcode:1998ASPC..140..261L.
