Short description: Star in the constellation Andromeda
56 Andromedae, abbreviated 56 And, is a probable binary star[8] system in the northern constellation of Andromeda. 56 Andromedae is the Flamsteed designation. It has a combined apparent visual magnitude of 5.69,[2] which is just bright enough to be dimly visible to the naked eye under good seeing conditions. The distance to this system can be ascertained from its annual parallax shift, measured at 9.9 mas[1] with the Gaia space observatory, which yields a separation of 330 light years. It is moving further from the Earth with a heliocentric radial velocity of +62 km/s[5] and is traversing the celestial sphere at a relatively high rate of 0.183″ per year.[9] This pair is positioned near the line of sight to the open cluster NGC 752, located 1,490 light-years away.[10]
The brighter primary is an aging giant star[3] with a stellar classification of K0 III,[4] having exhausted the hydrogen at its core and evolved off the main sequence. It is a red clump giant, having undergone "helium flash" and is presently generating energy at its core through helium fusion.[11] The star is about 3.1[6] billion years old with a negligible observable rotation rate, so the rotation axis of the star is likely pointing towards us.[5] It has 1.3[6] times the mass of the Sun and has expanded to 11[5] times the Sun's radius The star is radiating 56[5] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,765 K.[3]
The faint secondary component is a magnitude 11.93 star located at an angular separation of 18.50″ along a position angle (PA) of 77°, as of 2001. This has changed little since 1903 when it was at a separation of 18.4″ along a PA of 80°.[12]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.
- ↑ 2.0 2.1 2.2 2.3 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Da Silva, Ronald et al. (2015), "Homogeneous abundance analysis of FGK dwarf, subgiant, and giant stars with and without giant planets", Astronomy & Astrophysics 580: A24, doi:10.1051/0004-6361/201525770, Bibcode: 2015A&A...580A..24D.
- ↑ 4.0 4.1 Cottrell, P. L.; Sneden, C. (June 1986), "A detailed kinematic and abundance analysis of old disk giants", Astronomy and Astrophysics 161: 314−326, Bibcode: 1986A&A...161..314C.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Massarotti, 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, doi:10.1088/0004-6256/135/1/209, Bibcode: 2008AJ....135..209M.
- ↑ 6.0 6.1 6.2 6.3 Feuillet, Diane K. et al. (2016), "Determining Ages of APOGEE Giants with Known Distances", The Astrophysical Journal 817 (1): 40, doi:10.3847/0004-637X/817/1/40, Bibcode: 2016ApJ...817...40F.
- ↑ "56 And". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=56+And.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Lépine, Sébastien; Shara, Michael M. (March 2005), "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)", The Astronomical Journal 129 (3): 1483–1522, doi:10.1086/427854, Bibcode: 2005AJ....129.1483L.
- ↑ Kharchenko, N. V. et al. (2005), "Astrophysical parameters of Galactic open clusters", Astronomy and Astrophysics 438 (3): 1163–1173, doi:10.1051/0004-6361:20042523, Bibcode: 2005A&A...438.1163K.
- ↑ Mishenina, T. V. et al. (September 2006), "Elemental abundances in the atmosphere of clump giants", Astronomy and Astrophysics 456 (3): 1109–1120, doi:10.1051/0004-6361:20065141, Bibcode: 2006A&A...456.1109M.
- ↑ Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466–3471, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M.
External links
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