The two stars in this system orbit very close to each other; their spectrum cannot be separated and as a whole they have a spectrum of an F5V star. They are in marginal contact,[7] and there is a mass flow from the primary star to the secondary at a rate of 1.4 × 10−7M☉ yr−1.[6] The binary orbit is slowly decaying at rate 1.5*10−7 days/year. The third suspected component of the system is the red dwarf star with mass about 0.11 M☉, at 38±4 years orbit around binary.
[8]
Variability
Confirmation of the variability of CN Andromedae was announced by R. Weber in 1956.[9]
The light curve of the star shows a primary eclipse, with its brightness dropping down to 10.21 magnitude, and a secondary one down to a magnitude of 9.9.[3] This phenomenon repeats with a cycle of approximately 11.1 hours, with period decreasing in time due to the mass transfer from one star to the other.[6]
^ abcdeCN And, database entry, Combined General Catalog of Variable Stars (GCVS4.2, 2004 Ed.), N. N. Samus, O. V. Durlevich, et al., CDS ID II/250 Accessed on line 2018-10-17.
^ abcHøg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy & Astrophysics, 355: L27 –L30, Bibcode:2000A&A...355L..27H.
^ abcCutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues. 2246: II/246. Bibcode:2003yCat.2246....0C.
^ abcdefghiSiwak, M.; Zola, S.; Koziel-Wierzbowska, D. (2010). "A Study of Contact Binaries with Large Temperature Differences between Components". Acta Astronomica. 60 (4): 305–336. arXiv:1011.5682. Bibcode:2010AcA....60..305S.
