12 Persei


12 Persei
Perseus constellation map.svg
Red circle.svg
Location of 12 Persei (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Perseus
Right ascension 02h 42m 14.91569s[1]
Declination +40° 11′ 38.1898″[1]
Apparent magnitude (V) 4.94[2]
Spectral type F9 V[3]
U−B color index +0.08[2]
B−V color index +0.56[2]
Radial velocity (Rv)5.20[4] km/s
Proper motion (μ) RA: −17.20[1] mas/yr
Dec.: −183.30[1] mas/yr
Parallax (π)41.34 ± 0.43[1] mas
Distance78.9 ± 0.8 ly
(24.2 ± 0.3 pc)
Period (P)330.98[5] d
Semi-major axis (a)53.18[6] mas
Eccentricity (e)0.663[5]
Inclination (i)127.17[6]°
12 Per A
Mass1.382±0.019[5] M
Radius1.55[5] R
Luminosity3.02[5] L
Surface gravity (log g)4.20±0.10[5] cgs
Temperature6195±200[5] K
Metallicity [Fe/H]≥0.35[5] dex
Rotational velocity (v sin i)13[7] km/s
Age1.12[5] Gyr
12 Per B
Mass1.240±0.017[5] M
Radius1.31[5] R
Luminosity1.86[5] L
Surface gravity (log g)4.30±0.10[5] cgs
Temperature6000±200[5] K
Other designations
12 Per, BD+39° 610, FK5 2187, GJ 105.6 АВ, HD 16739, HIP 12623, HR 788, SAO 55793.[8]
Database references

12 Persei (12 Per) is a double-lined spectroscopic binary star system in the northern constellation Perseus. Its combined apparent magnitude is 4.94,[2] which means it can be viewed with the naked eye. Based upon parallax measurements, this system is about 79 light years away from the Sun.[1]

The magnitude difference between the two components is estimated to be 0.51. Based upon this, the primary has a mass around 138% of the Sun, 155% of the Sun's radius, and shines with three times the Sun's luminosity. The smaller secondary component is also larger than the Sun, with 124% of the Sun's mass, 131% of the radius of the Sun, and has 186% of the Sun's luminosity.[5] The stellar classification of the primary is F9 V,[3] which suggests it is an F-type main sequence star. The pair have an estimated age of just over a billion years.[5]

The pair orbit each other with a period of 331 days and an eccentricity of 0.663.[5] The semimajor axis of their orbit is 1.27 AU, which means the inner stability radius for a hypothetical planet orbiting the pair would be at 4.35 AU. This lies outside the habitability zone for this system.[9]


  1. ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
  2. ^ a b c d Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", SIMBAD Astronomical Database, Bibcode:1986EgUBV........0M.
  3. ^ a b Abt, Helmut A. (2009), "MK Classifications of Spectroscopic Binaries", The Astrophysical Journal Supplement, 180 (1): 117–118, Bibcode:2009ApJS..180..117A, doi:10.1088/0067-0049/180/1/117.
  4. ^ Pourbaix, D.; et al. (September 2004), "SB9: The ninth catalogue of spectroscopic binary orbits", Astronomy and Astrophysics, 424: 727–732, arXiv:astro-ph/0406573, Bibcode:2004A&A...424..727P, doi:10.1051/0004-6361:20041213, S2CID 119387088.
  5. ^ a b c d e f g h i j k l m n o p q Leushin, V. V.; Kuznetsov, M. K. (2008), "Chemical Composition and Evolutionary Status of Spectral Binary Star 12 Per", Odessa Astronomical Publications, 21: 57, Bibcode:2008OAP....21...57L.
  6. ^ a b Bagnuolo, William G., Jr.; et al. (June 2006), "The star 12 Persei and separated fringe packet binaries (SFPB)", in Monnier, John D.; Schöller, Markus; Danchi, William C. (eds.), Advances in Stellar Interferometry, Proceedings of the SPIE, vol. 6268, pp. 62682T, Bibcode:2006SPIE.6268E..2TB, doi:10.1117/12.672275, S2CID 124256072, 62682T.
  7. ^ Bernacca, P. L.; Perinotto, M. (1970), "A catalogue of stellar rotational velocities", Contributi Osservatorio Astronomico di Padova in Asiago, 239 (1): 1, Bibcode:1970CoAsi.239....1B.
  8. ^ "* 12 Per". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-07-21.{{cite web}}: CS1 maint: postscript (link)
  9. ^ Jaime, Luisa G.; et al. (September 2014), "Habitable zones with stable orbits for planets around binary systems", Monthly Notices of the Royal Astronomical Society, 443 (1): 260–274, arXiv:1401.1006, Bibcode:2014MNRAS.443..260J, doi:10.1093/mnras/stu1052.