28 Andromedae is anA-typegiant star,[3] meaning it is colored bluish-white. Parallax estimates made by theHipparcos spacecraft put the star at a distance of about 199light years (61parsecs).[1] It is moving towards the solar system at a velocity of10.30 km/s.[6]
Theblue bandlight curve, normalized to zero mean, of 28 Andromedae, adapted from Garridoet al.[12]
Two stars near 28 Andromedae share a common proper motion with the primary star, which is then a candidate triple system. The orbital parameters are currently unknown. The second and third component have masses of 0.71 M☉ and 0.14 M☉ respectively.[13]
28 Andromedae A is aDelta Scuti variable, so it displays small luminosity variations at timescales less than a day due to star pulsation. There is evidence for two periodic cycles of 5,014 and 5,900seconds, respectively. The amplitude variations, though, are not constant in time, and the pulsation modes are not radial.[14]
^Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars".Astronomy and Astrophysics.355:L27 –L30.Bibcode:2000A&A...355L..27H.
^abMermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)".Catalogue of Eggen's UBV Data.Bibcode:1986EgUBV........0M.
^Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)".VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S.1: B/GCVS.Bibcode:2009yCat....102025S.
^abDavid, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets".The Astrophysical Journal.804 (2): 146.arXiv:1501.03154.Bibcode:2015ApJ...804..146D.doi:10.1088/0004-637X/804/2/146.S2CID33401607.
^Rodriguez, E.; Rolland, A.; Lopez-Gonzalez, M. J.; Costa, V. (1998). "Extreme amplitude variations in 28 And".Astronomy and Astrophysics.338:905–908.Bibcode:1998A&A...338..905R.
