8 Persei


8 Persei is a single[8] star in the northern constellation of Perseus,[7] located 416 light years away from the Sun.[1] It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.757.[2] There is an estimated 52% chance that the star may be a member of the HyadesPleiades stream of co-moving stars.[9]

8 Persei
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Perseus
Right ascension 02h 17m 59.88750s[1]
Declination +57° 53′ 59.3529″[1]
Apparent magnitude (V) 5.757[2]
Spectral type K3 III[3]
B−V color index 1.203[2]
Radial velocity (Rv)0.72[2] km/s
Proper motion (μ) RA: +60.568[1] mas/yr
Dec.: +5.812[1] mas/yr
Parallax (π)7.8492 ± 0.1017 mas[1]
Distance416 ± 5 ly
(127 ± 2 pc)
Absolute magnitude (MV)0.26[4]
Mass1.83[2] M
Radius15.85±0.99[5] R
Luminosity107.95±1.69[1] L
Surface gravity (log g)2.3[5] cgs
[1] K
Metallicity [Fe/H]−0.07[5] dex
Rotational velocity (v sin i)1.0[6] km/s
Age2.36[2] Gyr
Other designations
8 Per, BD+57°535, FK5 2157, HD 13982, HIP 10718, HR 661, SAO 23143[7]
Database references

With an age of over two billion years,[2] this is an aging red giant of spectral type K3 III,[3] a star that has used up its core hydrogen and is expanding. It has 1.83[2] times the mass of the Sun and has reached nearly 16[5] times the Sun's size. The star is radiating 108[1] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,560 K.[1]


  1. ^ a b c d e f g h i j Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. ^ a b c d e f g h Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", Astronomical Journal, 150 (3), 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114.
  3. ^ a b Appenzeller, Immo (April 1967), "MK Spectral Types for 185 Bright Stars", Publications of the Astronomical Society of the Pacific, 79 (467): 102, Bibcode:1967PASP...79..102A, doi:10.1086/128449
  4. ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  5. ^ a b c d Baines, Ellyn K.; et al. (September 2016), "Spectroscopic and Interferometric Measurements of Nine K Giant Stars", The Astronomical Journal, 152 (3): 8, arXiv:1609.02379, Bibcode:2016AJ....152...66B, doi:10.3847/0004-6256/152/3/66, S2CID 52904703, 66.
  6. ^ De Medeiros, J. R.; et al. (November 2000), "Rotation and lithium in single giant stars", Astronomy and Astrophysics, 363: 239–243, arXiv:astro-ph/0010273, Bibcode:2000A&A...363..239D.
  7. ^ a b "8 Per". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-28.
  8. ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
  9. ^ Famaey, B.; et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430 (1): 165–186, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272, S2CID 17804304.