The primary member is asubgiant star that is somewhat larger than theSun and has just begun to evolve away from themain sequence as the supply of hydrogen at its core becomes exhausted. It is orbited by a smaller companion star at a meanangular separation of 1.5 arcseconds, which corresponds to a physical separation of about 15Astronomical Units.[6] This distance is large enough so that the two stars do not have a significant tidal effect on each other. The stars orbit each other over aperiod of 34.45 years, with asemi-major axis of 1.33" and aneccentricity of 0.46.[7]
Component A has astellar classification of F9 IV.[3] It has about 2.7 times the radius of the Sun and 1.45 times the Sun's mass. This star is radiating more than seven times the luminosity of the Sun at aneffective temperature of 5,760 K.[9][6] The secondary component (Component B) is about the same size and mass as the Sun, with an effective temperature of 5,300 K. Both stars are rotating slowly.[6] There may be a faint third member of this system, although little is known about it.[11]
The dual nature of this system was reported byF. G. W. Struve in 1826.[12] The pair orbit each other with aperiod of 34.45 years and aneccentricity of 0.46.[7] The magnitude difference between the A-B pair is 1.52 ± 0.04magnitudes (at 700nm).[13] Twoastrometric studies have failed to detect a third component to the A-B binary.[13][7]
^abcdJohnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars",Communications of the Lunar and Planetary Laboratory,4 (99): 99,Bibcode:1966CoLPL...4...99J
^abPizzolato, N.; Maggio, A.; Sciortino, S. (September 2000), "Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases",Astronomy and Astrophysics,361:614–628,Bibcode:2000A&A...361..614P
^abcdSöderhjelm, Staffan (January 1999), "Visual binary orbits and masses POST HIPPARCOS",Astronomy and Astrophysics,341:121–140,Bibcode:1999A&A...341..121S
^Barry, Don C.; Cromwell, Richard H.; Hege, E. Keith (April 1987), "Chromospheric activity and ages of solar-type stars",Astrophysical Journal, Part 1,315:264–272,Bibcode:1987ApJ...315..264B,doi:10.1086/165131
^Zhuchkov, R. Ya.; Orlov, V. V.; Rubinov, A. V. (May 2006), "Multiple stars with low hierarchy: stable or unstable?",Publications of the Astronomical Observatory of Belgrade,80:155–160,Bibcode:2006POBeo..80..155Z
^de Mello, G. F. Porto; da Silva, L. (1991), "On the physical existence of the Zeta HER moving group - A detailed analysis of Phi exp 2 Pavonis",Astronomical Journal,102:1816–1825,Bibcode:1991AJ....102.1816P,doi:10.1086/116006
