Xi Persei

Xi Persei (ξ Persei, abbreviated Xi Per, ξ Per), also named Menkib,[8] is a star in the constellation of Perseus. Based upon parallax measurements taken during the Hipparcos mission, it is approximately 1,200 light-years from the Sun.

Perseus constellation map
Red circle.svg
Location of ξ Persei (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Perseus
Right ascension 03h 58m 57.90229s[1]
Declination +35° 47′ 27.7132″[1]
Apparent magnitude (V) 4.04[2]
Spectral type O7.5III(n)((f))[3]
U−B color index −0.93[2]
B−V color index +0.02[2]
Variable type slightly variable[4]
Radial velocity (Rv) 65.40[5] km/s
Proper motion (μ) RA: 3.62[1] mas/yr
Dec.: 1.74[1] mas/yr
Parallax (π) 2.62 ± 0.51[1] mas
Distance approx. 1,200 ly
(approx. 380 pc)
Absolute magnitude (MV) −5.50[3]
Mass 26[3]-36[6] M
Radius 14[6] R
Luminosity 263,000[3] L
Surface gravity (log g) 3.5[3] cgs
Temperature 35,000[6] K
Rotational velocity (v sin i) 220[3] km/s
Age ~7[7] Myr
Other designations
46 Per, HR 1228, HD 24912, FK5 148, SAO 56856, HIP 18614, BD+35°775
Database references


ξ Persei (Latinised to Xi Persei) is the star's Bayer designation.

It bore the traditional name Menkib, Menchib, Menkhib or Al Mankib, from Mankib al Thurayya (Arabic for "shoulder" [of the Pleiades]). In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[9] to catalogue and standardize proper names for stars. The WGSN approved the name Menkib for this star on 12 September 2016 and it is now so included in the List of IAU-approved Star Names.[8]

In Chinese, 卷舌 (Juǎn Shé), meaning Rolled Tongue, refers to an asterism consisting of Xi Persei, Nu Persei, Epsilon Persei, Zeta Persei, Omicron Persei and 40 Persei.[10] Consequently, Xi Persei itself is known as 卷舌三 (Juǎn Shé sān, "the Third Star of Rolled Tongue").[11]


Xi Persei has an apparent magnitude of +4.06 and is classified as a blue giant (spectral class O7.5III). It is intrinsically 12,700 times brighter than the Sun with absolute magnitude -5.5 in the V band. If the ultraviolet light that emanates from Menkib is included, its total bolometric luminosity is 263,000 times that of the Sun.

The star has a mass of some 30 solar masses and a surface temperature of 35,000 kelvins, making it one of the hottest stars that can be seen with the naked eye. The fluorescence of the California Nebula (NGC 1499) is due to this star’s prodigious radiation.[7]


  1. ^ a b c d e Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653. arXiv:0708.1752Freely accessible. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
  2. ^ a b c 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: 0. Bibcode:2002yCat.2237....0D.
  3. ^ a b c d e f Repolust, T.; Puls, J.; Herrero, A. (2004). "Stellar and wind parameters of Galactic O-stars. The influence of line-blocking/blanketing". Astronomy and Astrophysics. 415 (1): 349–376. Bibcode:2004A&A...415..349R. doi:10.1051/0004-6361:20034594.
  4. ^ Ramiaramanantsoa, Tahina; Moffat, Anthony F. J.; Chené, André-Nicolas; Richardson, Noel D.; Henrichs, Huib F.; Desforges, Sébastien; Antoci, Victoria; Rowe, Jason F.; Matthews, Jaymie M.; Kuschnig, Rainer; Weiss, Werner W.; Sasselov, Dimitar; Rucinski, Slavek M.; Guenther, David B. (2014). "MOST detects corotating bright spots on the mid-O-type giant ξ Persei". Monthly Notices of the Royal Astronomical Society. 441: 910. arXiv:1403.7843Freely accessible. Bibcode:2014MNRAS.441..910R. doi:10.1093/mnras/stu619.
  5. ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759. arXiv:1606.08053Freely accessible. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065.
  6. ^ a b c Krticka, J.; Kubat, J. (2010). "Comoving frame models of hot star winds. I. Test of the Sobolev approximation in the case of pure line transitions". Astronomy and Astrophysics. 519: A50. arXiv:1005.0258Freely accessible. Bibcode:2010A&A...519A..50K. doi:10.1051/0004-6361/201014111.
  7. ^ a b Hoogerwerf, R.; De Bruijne, J. H. J.; De Zeeuw, P. T. (2001). "On the origin of the O and B-type stars with high velocities. II. Runaway stars and pulsars ejected from the nearby young stellar groups". Astronomy and Astrophysics. 365 (2): 49. arXiv:astro-ph/0010057Freely accessible. Bibcode:2001A&A...365...49H. doi:10.1051/0004-6361:20000014.
  8. ^ a b "Naming Stars". IAU.org. Retrieved 16 December 2017.
  9. ^ IAU Working Group on Star Names (WGSN), International Astronomical Union, retrieved 22 May 2016.
  10. ^ (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
  11. ^ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 Archived 2008-10-25 at the Wayback Machine., Hong Kong Space Museum. Accessed on line November 23, 2010.

External links

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