40 Persei


40 Persei
Perseus IAU.svg
Red circle.svg
Location of 40 Persei (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Perseus
Right ascension 03h 42m 22.64555s[1]
Declination 33° 57′ 54.0893″[1]
Apparent magnitude (V) 4.97[2]
Spectral type B0.5V[3] + A1Vn[4]
U−B color index −0.84[5]
B−V color index +0.00[5]
Radial velocity (Rv)+22.00[6] km/s
Proper motion (μ) RA: +2.71[1] mas/yr
Dec.: −5.91[1] mas/yr
Parallax (π)3.09 ± 0.21[1] mas
Distance1,060 ± 70 ly
(320 ± 20 pc)
Absolute magnitude (MV)−2.26[2]
40 Per A
Mass12.5[7] M
Luminosity936[2] L
Surface gravity (log g)4.36[8] cgs
Temperature29,330[9] K
Metallicity [Fe/H]−0.43[2] dex
Rotational velocity (v sin i)10[10] km/s
Age7.2[11] Myr
Other designations
40 Per, BD+33°698, GC 4420, HD 22951, HIP 17313, HR 1123, SAO 56646, CCDM J03424+3358A, WDS J03424+3358A[12]
Database references

40 Persei is a wide binary star[13] system in the northern constellation of Perseus. It has the Bayer designation ο Persei, while 40 Persei is the Flamsteed designation. The system is visible to the naked eye as a faint, blue-white hued point of light with an apparent visual magnitude of 4.97.[2] It is located approximately 1060 light years away from the Sun based on parallax,[1] and is drifting further away with a radial velocity of +22 km/s.[6] The system is a member of the Perseus OB2 association of co-moving stars.[14]

The primary component is a massive B-type main-sequence star with a stellar classification of B0.5V.[3] It is about 7.2[11] million years old and has a very low projected rotational velocity for an early B-type star,[15] measured at 10 km/s.[10] This star has 12.5[7] times the mass of the Sun and is radiating 936[2] times the Sun's luminosity from its photosphere at an effective temperature of 29,330 K.[9] The companion is magnitude 10.04, A-type main-sequence star with a class of A1Vn, and is located at an angular separation of 19.8 from the primary.[4]


  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. Vizier catalog entry
  2. ^ a b c d e f 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. Vizier catalog entry
  3. ^ a b Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H. 5050. Bibcode:1995yCat.5050....0H.
  4. ^ a b Mason, Brian D.; et al. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. Vizier catalog entry
  5. ^ a b Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers. 42 (2): 443. Bibcode:2014JAVSO..42..443M.Vizier catalog entry
  6. ^ a b Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
  7. ^ a b Tetzlaff, N.; et al. (2011). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1): 190–200. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. S2CID 118629873. {{cite journal}}: |last2= has generic name (help) Vizier catalog entry
  8. ^ Soubiran, Caroline; et al. (2016). "The PASTEL catalogue: 2016 version". Astronomy & Astrophysics. 591: A118. arXiv:1605.07384. Bibcode:2016A&A...591A.118S. doi:10.1051/0004-6361/201628497. S2CID 119258214.
  9. ^ a b Zorec, J.; et al. (2009). "Fundamental parameters of B supergiants from the BCD system". Astronomy and Astrophysics. 501: 297–320. arXiv:0903.5134. Bibcode:2009A&A...501..297Z. doi:10.1051/0004-6361/200811147. S2CID 14969137.
  10. ^ a b Abt, Helmut A.; et al. (2002). "Rotational Velocities of B Stars". The Astrophysical Journal. 573 (1): 359–365. Bibcode:2002ApJ...573..359A. doi:10.1086/340590.
  11. ^ a b Seyfert, C. K.; et al. (July 1960). "A Study of the II Persei Association". Astrophysical Journal. 132: 58. Bibcode:1960ApJ...132...58S. doi:10.1086/146900.
  12. ^ "40 Per". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-07-18.
  13. ^ 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.
  14. ^ Lesh, J. R. (September 1969). "Internal motions in the associations II Per and I Lac". Astronomical Journal. 74: 891–898. Bibcode:1969AJ.....74..891L. doi:10.1086/110878.
  15. ^ Guthrie, B. N. G. (September 1984). "The rotation of early B-type stars and the problem of star formation". Monthly Notices of the Royal Astronomical Society. 210: 159–171. Bibcode:1984MNRAS.210..159G. doi:10.1093/mnras/210.1.159.