Mu Persei


Mu Persei, Latinised from μ Persei, is a binary star system in the northern constellation of Perseus. It is visible to the naked eye as a point of light with a combined apparent visual magnitude of +4.16.[2] The distance to this system is approximately 900 light-years based on parallax measurements.[1] It is drifting further away with a radial velocity of +26 km/s.[6]

Mu Persei
Perseus IAU.svg
Red circle.svg
Location of μ Persei (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Perseus
Right ascension 04h 14m 53.86253s[1]
Declination +48° 24′ 33.5912″[1]
Apparent magnitude (V) +4.16[2]
Spectral type G0Ib[3] + B9.5[4]
B−V color index 0.935±0.002[5]
Radial velocity (Rv)26.46[6] km/s
Proper motion (μ) RA: 5.52[1] mas/yr
Dec.: −17.37[1] mas/yr
Parallax (π)3.62 ± 0.20 mas[1]
Distance900 ± 50 ly
(280 ± 20 pc)
Absolute magnitude (MV)−3.08[5]
Period (P)284 d
Semi-major axis (a)18.8 ± 8.8 mas
Eccentricity (e)0.062
Inclination (i)74 ± 24°
Longitude of the node (Ω)296 ± 18°
Periastron epoch (T)2,420,062
Argument of periastron (ω)
Radius~53[8] R
Luminosity~2030[8] L
Surface gravity (log g)1.74[9] cgs
Temperature5418[9] K
Metallicity [Fe/H]0.09[9] dex
Rotational velocity (v sin i)12[10] km/s
Other designations
Mu Per, μ Per, 51 Persei, NSV 1518, BD+48 1063, FK5 1117, GC 5099, HD 26630, HIP 19812, HR 1303, SAO 39404, PPM 46912, CCDM J04149+4824A, WDS J04149+4825A[11]
Database references

Mu Persei is a spectroscopic binary with an orbital period of 284 days and an eccentricity of about 0.06.[7] The primary component is a yellow G-type supergiant star. With an effective temperature of about 5,400 K and a radius of 53 solar radii, this star has the luminosity of about 2,030 times that of the Sun.[8] The companion is a B-type star with a class of B9.5[4]

Mu Persei is moving through the galaxy at a speed of 35.6 km/s relative to the Sun. Its projected galactic orbit carries it between 23,900 and 32,400 light-years from the center of the galaxy.[12]

Mu Persei came closest to the Sun 5.6 million years ago when it had brightened to magnitude 3.25 from a distance of 600 light-years.[12]


In Chinese, 天船 (Tiān Chuán), meaning Celestial Boat, refers to an asterism consisting of μ Persei, η Persei, γ Persei, α Persei, ψ Persei, δ Persei, 48 Persei and HD 27084. Consequently, μ Persei itself is known as 天船七 (Tiān Chuán qī, English: the Seventh Star of Celestial Boat).[13]


  1. ^ a b c d e f van Leeuwen, F.; et al. (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 Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
  3. ^ 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.
  4. ^ a b Pantaleoni González, M.; Maíz Apellániz, J.; Barbá, R. H.; Negueruela, I. (January 2020). "A Catalog of Galactic Multiple Systems with a Red Supergiant and a B Star". Research Notes of the AAS. 4 (1). arXiv:2001.11680. Bibcode:2020RNAAS...4...12P. doi:10.3847/2515-5172/ab712b. 12.
  5. ^ a b 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.
  6. ^ a b Soubiran, C.; Bienaymé, O.; Mishenina, T. V.; Kovtyukh, V. V. (2008). "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants". Astronomy and Astrophysics. 480 (1): 91–101. arXiv:0712.1370. Bibcode:2008A&A...480...91S. doi:10.1051/0004-6361:20078788. S2CID 16602121.
  7. ^ a b Alden, Harold L. (1925). "Apparent orbit of μ Persei". Astronomical Journal. 36 (851): 81–82. Bibcode:1925AJ.....36...81A. doi:10.1086/104676.
  8. ^ a b c MU PER (Mu Persei)
  9. ^ a b c Luck, R. Earle (2014). "Parameters and Abundances in Luminous Stars". The Astronomical Journal. 147 (6): 137. Bibcode:2014AJ....147..137L. doi:10.1088/0004-6256/147/6/137.
  10. ^ de Medeiros, J. R.; Udry, S.; Burki, G.; Mayor, M. (2002). "A catalog of rotational and radial velocities for evolved stars. II. Ib supergiant stars" (PDF). Astronomy and Astrophysics. 395: 97–98. Bibcode:2002A&A...395...97D. doi:10.1051/0004-6361:20021214.
  11. ^ "* mu. Per". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 23 February 2017.
  12. ^ a b Mu Persei (HIP 19812) Archived 2013-04-14 at
  13. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日