A stellar companion was detected in 1986 and reported in 1989.[13] This fainter companion is separated from Theta Andromedae by 0.06 arcseconds.[11] The secondary appears to be a massive, possibly A-type, star orbiting at a distance of around oneastronomical unit with aperiod of 2.83 years and a largeorbital eccentricity (ovalness) of 0.95.[8]
InChinese,天廄 (Tiān Jiù), meaningCelestial Stable, refers to an asterism consisting of θ Andromedae,ρ Andromedae andσ Andromedae. Consequently, theChinese name for θ Andromedae itself is known as天廄一 (Tiān Jiù yī, English:the First Star of Celestial Stable.)[14]
^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.
^abCowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications",Astronomical Journal,74:375–406,Bibcode:1969AJ.....74..375C,doi:10.1086/110819.
^abcKoçer, D.; et al. (2003), "Elemental abundance analyses with DAO spectrograms-XXVII. The superficially normal stars θ And (A2 IV), ϵ Del (B6 III), ϵ Aqr (A1. 5 V), and ι And (B9 V)",Astronomy & Astrophysics,406 (3):975–980,Bibcode:2003A&A...406..975K,doi:10.1051/0004-6361:20030620.
^Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick (eds.),Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, vol. 30, University of Toronto:International Astronomical Union, p. 57,Bibcode:1967IAUS...30...57E.
^abcdHill, G. M. (February 1995), "Compositional differences among the A-type stars. 2: Spectrum synthesis up to V sin i = 110 km/s",Astronomy and Astrophysics,294 (2):536–546,Bibcode:1995A&A...294..536H.
^Palous, J.; Hauck, B. (July 1986), "The Sirius supercluster",Astronomy and Astrophysics,162:54–61,Bibcode:1986A&A...162...54P.
^McAlister, Harold A.; et al. (February 1989), "ICCD Speckle Observations of Binary Stars. IV. Measurements During 1986-1988 from the Kitt Peak 4-m Telescope",Astronomical Journal,97: 510,Bibcode:1989AJ.....97..510M,doi:10.1086/115001.
