The visible component is ared giant star and has been defined as a standard star for thestellar classification of K6 IIIa.[6] Prior to that there had been no spectral standard for K6 giants and HD 3346 had been classified between K5 III and M0 III.[16]
In 1996 it was announced that the variations inradial velocity of this star were larger than expected. Two orbiting companions were proposed to explain this variation, the one known since 1985 with a period of about 650 days and aminimum mass of about60MJ, and a second one with a period of about 14-40 days and a minimum mass of about10MJ.[17][18] The existence of this second, possiblyplanetary companion was never confirmed.
In 1982, HD 3346 was listed as a suspected variable star (NSV 15135) in Pavel Nikolaevich Kholopov's catalog of suspected variable stars.[19] Gregory W. Henryet al. confirmed that the star is variable in year 2000.[20] It was given itsvariable star designation, V428 Andromedae, in 2003.[21]
It is a short-periodsemi-regular variable (type SRS),[4] also called an ultra-small-amplitude pulsating red giant.[22] It has an amplitude of only 0.065 magnitudes.[22] The main pulsation period is 11.5 days, but other periods of 11, 15, and 22 days have been detected.[23][22]
^abKeenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars".Astrophysical Journal Supplement Series.71: 245.Bibcode:1989ApJS...71..245K.doi:10.1086/191373.
^Khalatyan, A.; Anders, F.; Chiappini, C.; Queiroz, A. B. A.; Nepal, S.; Dal Ponte, M.; Jordi, C.; Guiglion, G.; Valentini, M.; Torralba Elipe, G.; Steinmetz, M.; Pantaleoni-González, M.; Malhotra, S.; Jiménez-Arranz, Ó.; Enke, H.; Casamiquela, L.; Ardèvol, J. (2024). "Transferring spectroscopic stellar labels to 217 million Gaia DR3 XP stars with SHBoost".Astronomy and Astrophysics.691: A98.arXiv:2407.06963.Bibcode:2024A&A...691A..98K.doi:10.1051/0004-6361/202451427.
^De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (2014). "A catalog of rotational and radial velocities for evolved stars. V. Southern stars".Astronomy and Astrophysics.561: A126.arXiv:1312.3474.Bibcode:2014A&A...561A.126D.doi:10.1051/0004-6361/201220762.
^Kordopatis, G.; Schultheis, M.; McMillan, P. J.; Palicio, P. A.; De Laverny, P.; Recio-Blanco, A.; Creevey, O.; Álvarez, M. A.; Andrae, R.; Poggio, E.; Spitoni, E.; Contursi, G.; Zhao, H.; Oreshina-Slezak, I.; Ordenovic, C.; Bijaoui, A. (2023). "Stellar ages, masses, extinctions, and orbital parameters based on spectroscopic parameters of Gaia DR3".Astronomy and Astrophysics.669: A104.arXiv:2206.07937.Bibcode:2023A&A...669A.104K.doi:10.1051/0004-6361/202244283.
^Kholopov, P. N. (1982).New catalogue of stars suspected of variability containing data on 14810 variable stars which have not received definite nomenclature until 1980. Moskva: Nauka. p. 359.Bibcode:1982ncss.book.....K.
^abcPercy, John R.; et al. (December 2001), "Periods of Eleven K5-M0 Pulsating Red Giants",Information Bulletin on Variable Stars,5209: 1,Bibcode:2001IBVS.5209....1P
