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Star in the constellation Andromeda
ε Andromedae
Location of ε Andromedae (circled)
Observation dataEpoch J2000.0 Equinox J2000.0 (ICRS )
Constellation
Andromeda
Right ascension 00h 38m 33.347s [ 1]
Declination
+29° 18′ 42.31″[ 1]
Apparent magnitude (V)4.357[ 2]
Characteristics
Evolutionary stage
red clump [ 3]
Spectral type
G6 III Fe−3 CH1 [ 4]
U−B color index
+0.463[ 2]
B−V color index
+0.8713[ 2]
V−R color index
+0.6[ 5]
R−I color index
+0.51[ 6]
Astrometry Radial velocity (Rv )± 0.15[ 7] km/s Proper motion (μ) RA: −228.701 mas /yr [ 1] Dec.: −253.206 mas /yr [ 1] Parallax (π)19.2451± 0.1188 mas [ 1] Distance 169 ± 1 ly pc ) Absolute magnitude (MV )+0.69[ 8] Details[ 7] Mass ± 0.35M ☉ Radius ± 0.34R ☉ Luminosity 51.3 L ☉ Surface gravity (log g )± 0.02cgs Temperature ± 20K Metallicity ± 0.05dex Rotational velocity (v sin i )± 0.45Age ± 5.29Gyr Other designations ε And, eps And , 30 Andromedae , BD +28°103FK5 19GC 759HD 3546HIP 3031HR 163SAO 74164PPM 90002LTT 10215NLTT 2065[ 5] Database references SIMBAD data
Epsilon Andromedae is a star in the constellation of Andromeda .[ 5] Bayer designation that is Latinized from ε Andromedae , and abbreviated eps And or ε And, respectively. This star can be seen with the naked eye, having an apparent visual magnitude of 4.4.[ 2] parallax shift of 19.2 mas as seen from Earth,[ 1] light years from the Sun . The system is moving closer to the Sun with a radial velocity of −84 km/s.[ 7] orbit in the Milky Way is highly eccentric , causing it to move rapidly relative to the Sun and its neighboring stars.[ 9]
This is an evolved G-type giant star with a stellar classification of G6 III Fe−3 CH1 .[ 4] spectrum , and an overabundance of cyanogen (CN). ε Andromedae is believed to be a red clump [ 3] fusing helium in its core. It has about the same mass as the Sun , but has expanded to nine times the Sun's radius . The star is radiating 51 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 5,082 K.[ 7]
In Chinese , 奎宿 Kuí Sù Legs (asterism)η Andromedae , 65 Piscium , ζ Andromedae , δ Andromedae , π Andromedae , ν Andromedae , μ Andromedae , β Andromedae , σ Piscium , τ Piscium , 91 Piscium , υ Piscium , φ Piscium , χ Piscium and ψ¹ Piscium . Consequently, the Chinese name for ε Andromedae itself is 奎宿四 Kuí Sù sì the Fourth Star of Legs .)[ 10]
^ a b c d e Brown, A. G. A. ; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties" . Astronomy & Astrophysics 649 : A1. arXiv :2012.01533 Bibcode :2021A&A...649A...1G . doi :10.1051/0004-6361/202039657 S2CID 227254300 . (Erratum: doi :10.1051/0004-6361/202039657e ) . Gaia EDR3 record for this source at VizieR .^ a b c d Jennens, P. A.; Helfer, H. L. (September 1975). "A new photometric metal abundance and luminosity calibration for field G and K giants" . Monthly Notices of the Royal Astronomical Society . 172 (3): 667– 679. Bibcode :1975MNRAS.172..667J . doi :10.1093/mnras/172.3.667 ^ a b Puzeras, E.; et al. (October 2010). "High-resolution spectroscopic study of red clump stars in the Galaxy: iron-group elements" . Monthly Notices of the Royal Astronomical Society . 408 (2): 1225– 1232. arXiv :1006.3857 Bibcode :2010MNRAS.408.1225P . doi :10.1111/j.1365-2966.2010.17195.x S2CID 44228180 . ^ a b Keenan, 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 . ^ a b c "eps And" . SIMBAD Centre de données astronomiques de Strasbourg . Retrieved August 28, 2008 .^ HR 163 , database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50 . Accessed on line August 28, 2008.^ a b c d Jofré, E.; Petrucci, R.; Saffe, C.; Saker, L.; de la Villarmois, E. Artur; Chavero, C.; Gómez, M.; Mauas, P. J. D. (2015). "Stellar parameters and chemical abundances of 223 evolved stars with and without planets". Astronomy & Astrophysics . 574 : A50. arXiv :1410.6422 Bibcode :2015A&A...574A..50J . doi :10.1051/0004-6361/201424474 . S2CID 53666931 . ^ Takeda, Yoichi; et al. (August 2008). "Stellar Parameters and Elemental Abundances of Late-G Giants". Publications of the Astronomical Society of Japan . 60 (4): 781– 802. arXiv :0805.2434 Bibcode :2008PASJ...60..781T . doi :10.1093/pasj/60.4.781 . S2CID 16258166 . ^ Epsilon Andromedae Archived 2007-04-28 at the Wayback Machine , Stars , Jim Kaler. Accessed on line August 28, 2008.^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 19 日 Archived 2016-03-03 at the Wayback Machine
