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Saiph

Coordinates:Sky map05h47m45.4s,−09° 40′ 11″
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Saiph
Location of Saiph (circled)
Observation data
EpochJ2000EquinoxJ2000
Constellation Orion
Right ascension 05h47m45.38884s[1]
Declination −09° 40′ 10.5777″[1]
Apparent magnitude(V) 2.09[2]
Characteristics
Evolutionary stage Blue supergiant
Spectral type B0.5 Ia[3]
U−Bcolor index −1.02[2]
B−Vcolor index −0.18[2]
Variable type Suspected[4]
Astrometry
Radial velocity(Rv)+20.5[5]km/s
Proper motion(μ)RA:+1.46[1]mas/yr
Dec.:−1.28[1]mas/yr
Parallax(π)5.04 ± 0.22mas[1]
Distance650 ± 30ly
(198 ± 9pc)
Absolute magnitude(MV)−6.1[6]
Details
Mass15.5±1.25[7]or 21.1[8]M☉
Radius13–14[9]R☉
Luminosity60,300+10,500
−9,000[9]L☉
Surface gravity(logg)2.70±0.05[9]cgs
Temperature25,700±260[9]K
Rotational velocity(vsini)83[6]km/s
Age11.1±0.5[10]or 5.6[8]Myr
Other designations
κ Orionis, 53 Orionis, 141 G. Orionis,BD−09 1235,FK5220,HD38771,HIP27366,HR2004,SAO132542.[11]
Database references
SIMBADdata

Saiph/ˈseɪf/,designationKappa Orionis(κ Orionis,abbreviatedKappa Ori,κ Ori) and53 Orionis(53 Ori), is ablue supergiantstar and the sixth-brighteststarin theconstellationofOrion.Of the four bright stars that compose Orion's main quadrangle, it is the star at the south-eastern corner. A northern-hemisphere observer facing south would see it at the lower left of Orion, and a southern-hemisphere observer facing north would see it at the upper right.Parallaxmeasurements yield an estimated distance of 650light-years(200parsecs) from theSun.[1]It is smaller, less luminous but hotter at its surface thanRigelwith anapparent visual magnitudeof 2.1.[2]The luminosity of this star changes slightly, varying by 0.04 magnitudes.[4]

Nomenclature

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Kappa Orionisis the star'sBayer designationand53 OrionisitsFlamsteed designation.The traditional nameSaiphis from theArabicsaif al jabbar,'سیف الجبّار',literallysaifof thegiant.This name was originally applied toEta Orionis.[12]In 2016, theInternational Astronomical Unionorganized aWorking Group on Star Names(WGSN)[13]to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[14]included a table of the first two batches of names approved by the WGSN, which includedSaiphfor this star. It is now so entered in the IAU Catalog of Star Names.[15]

In the 17th-century catalogue of stars in theCalendariumofAl Achsasi al Mouakket,this star was designatedRekbah al Jauza al Yemeniat,which was translated intoLatinasGenu Dextrum Gigantis"right knee of the giant".[16]

Properties

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Saiph is asupergiantwith astellar classificationof B0.5 Ia. Theluminosity class'Ia' represents abright supergiantstar that has exhausted the supply of hydrogen at its core andevolvedaway from themain sequence.Saiph has a strongstellar windand is losing mass at the rate of9.0 × 10−7times the mass of the Sun per year, or the equivalent of the Sun's mass every 1.1 million years.[6]Using a combination of parallax as determined byHipparcosand thespectrumyields a mass 15.50 ± 1.25 times and luminosity 56,881 times that of the Sun.[7]Analysis of the spectra and age of the members of the Orion OB1 association yields a mass 28 times that of the Sun (from an original mass 31.8 times that of the Sun) and an age of 6.2 million years.[8]An analysis of the star'sspectral energy distributionusing the Hipparcos distance give a luminosity of 60,000L☉and a radius of 13R☉.[9]Large stars such as Saiph (and many other stars in Orion) are destined to collapse on themselves and explode assupernovae.[17]

In non-Western astronomy and culture

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InChinese,Tham túc(Shēn Sù), meaningThree Stars(asterism),refers to an asterism consisting of Saiph,Alnitak,Alnilam,Mintaka,Betelgeuse,BellatrixandRigel.[18]Consequently, theChinese namefor Saiph isTham túc sáu(Shēn Sù liù,English:the Sixth Star of Three Stars).[19]

TheWardaman peopleof northern Australia regard Saiph as the Guman digging stick, used to make a canyon by Black-headed Python.[20]

References

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  1. ^abcdefvan Leeuwen, F. (November 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,S2CID18759600
  2. ^abcdCrawford, D. L.; Barnes, J. V.; Golson, J. C. (1971), "Four-color, H-beta, and UBV photometry for bright B-type stars in the northern hemisphere",The Astronomical Journal,76:1058,Bibcode:1971AJ.....76.1058C,doi:10.1086/111220
  3. ^Morgan, W. W.; Keenan, P. C. (1973). "Spectral Classification".Annual Review of Astronomy and Astrophysics.11(1): 29–50.Bibcode:1973ARA&A..11...29M.doi:10.1146/annurev.aa.11.090173.000333.
  4. ^abLefèvre, L.; et al. (November 2009), "A systematic study of variability among OB-stars based on HIPPARCOS photometry",Astronomy and Astrophysics,507(2): 11411201,Bibcode:2009A&A...507.1141L,doi:10.1051/0004-6361/200912304
  5. ^Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions",Veröff. Astron. Rechen-Inst. Heidelb,35(35), Astronomisches Rechen-Institut Heidelberg: 1,Bibcode:1999VeARI..35....1W
  6. ^abcCrowther, P. A.; Lennon, D. J.; Walborn, N. R. (January 2006), "Physical parameters and wind properties of galactic early B supergiants",Astronomy and Astrophysics,446(1): 279–293,arXiv:astro-ph/0509436,Bibcode:2006A&A...446..279C,doi:10.1051/0004-6361:20053685,S2CID18815761
  7. ^abHohle, M. M.; Neuhäuser, R.; Schutz, B. F. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants",Astronomische Nachrichten,331(4): 349,arXiv:1003.2335,Bibcode:2010AN....331..349H,doi:10.1002/asna.200911355,S2CID111387483
  8. ^abcVoss, R.; Diehl, R.; Vink, J. S.; Hartmann, D. H. (2010). "Probing the evolving massive star population in Orion with kinematic and radioactive tracers".Astronomy and Astrophysics.520:10.arXiv:1005.3827.Bibcode:2010A&A...520A..51V.doi:10.1051/0004-6361/201014408.S2CID38599952.A51.
  9. ^abcdeHaucke, M.; Cidale, L. S.; Venero, R. O. J.; Curé, M.; Kraus, M.; Kanaan, S.; Arcos, C. (2018-06-01)."Wind properties of variable B supergiants - Evidence of pulsations connected with mass-loss episodes".Astronomy & Astrophysics.614:A91.arXiv:1902.01341.doi:10.1051/0004-6361/201731678.ISSN0004-6361.
  10. ^Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 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,S2CID118629873
  11. ^"SAIPH -- Variable Star",SIMBAD,Centre de Données astronomiques de Strasbourg,retrieved2012-01-12
  12. ^Allen, Richard Hinckley (1899).Star-names and their meanings.G. E. Stechert. p. 317.
  13. ^"IAU Working Group on Star Names (WGSN)".Retrieved22 May2016.
  14. ^"Bulletin of the IAU Working Group on Star Names, No. 1"(PDF).Retrieved28 July2016.
  15. ^"IAU Catalog of Star Names".Retrieved28 July2016.
  16. ^Knobel, E. B. (June 1895)."Al Achsasi Al Mouakket, on a catalogue of stars in the Calendarium of Mohammad Al Achsasi Al Mouakket".Monthly Notices of the Royal Astronomical Society.55(8): 429.Bibcode:1895MNRAS..55..429K.doi:10.1093/mnras/55.8.429.
  17. ^Kaler, James B.,"SAIPH (Kappa Orionis)",Stars,University of Illinois,retrieved2012-01-27
  18. ^(in Chinese)Trung Quốc chòm sao thần thoại,written by trần lâu kim. Published by Đài Loan thư phòng xuất bản công ty hữu hạn, 2005,ISBN978-986-7332-25-7.
  19. ^(in Chinese)AEEA (Activities of Exhibition and Education in Astronomy) thiên văn giáo dục tin tức võng 2006 năm 5 nguyệt 25 ngàyArchived2011-07-16 at theWayback Machine
  20. ^Harney, Bill Yidumduma; Cairns, Hugh C. (2004) [2003].Dark Sparklers(Revised ed.). Merimbula, New South Wales: Hugh C. Cairns. p. 139.ISBN0-9750908-0-1.


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