HD 221148 is suspected variable star in the equatorial constellation of Aquarius. The spectrum of the star shows exceptionally strong levels of CN; one of the highest cyanogen indices measured.[4]
^ abcMermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode:1986EgUBV........0M
^ abcdefghMassarotti, Alessandro; et al. (January 2008), "Rotational and radial velocities for a sample of 761 HIPPARCOS giants and the role of binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209
^Janes, K. A. (May 1975), "Cyanogen Strengths, Luminosities, and Kinematics of K Giant Stars", Astrophysical Journal Supplement, 29: 161–183, Bibcode:1975ApJS...29..161J, doi:10.1086/190339. See p. 179.{{citation}}: CS1 maint: postscript (link)