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Sigma Hydrae

January 06, 2023

Sigma Hydrae (σ Hydrae, abbreviated Sigma Hya, σ Hya), also named Minchir /ˈmɪŋkər/,[10] is a solitary[11] star in the equatorial constellation of Hydra. It is visible to the naked eye with an apparent visual magnitude of 4.48.[2] The estimated distance to this star from the Sun, based upon an annual parallax shift of 8.75 mas,[1] is around 370 light-years. At that distance, the visual magnitude of the star is diminished by an interstellar extinction factor of 0.16,[4] due to intervening dust.

Sigma Hydrae
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Hydra
Right ascension 08h 38m 45.43747s[1]
Declination +03° 20′ 29.1701″[1]
Apparent magnitude (V) 4.48[2]
Characteristics
Spectral type K2 III[3]
U−B color index +1.23[2]
B−V color index +1.21[2]
Astrometry
Radial velocity (Rv)27.28±0.19[4] km/s
Proper motion (μ) RA: −19.48[1] mas/yr
Dec.: −15.92[1] mas/yr
Parallax (π)8.75 ± 0.25 mas[1]
Distance370 ± 10 ly
(114 ± 3 pc)
Absolute magnitude (MV)−0.84[5]
Details[6]
Mass3.07 M☉
Radius27.6[7] R☉
Luminosity295 L☉
Surface gravity (log g)2.21±0.13[8] cgs
Temperature4,491±51 K
Metallicity [Fe/H]0.13±0.06[8] dex
Age430 Myr
Other designations
σ Hya, 5 Hydrae, BD+03°2026, FK5 1224, HD 73471, HIP 42402, HR 3418, SAO 116988.[9]
Database references
SIMBADdata

Nomenclature

σ Hydrae (Latinised to Sigma Hydrae) is the system's Bayer designation.

It bore the traditional name Minchir, appearing as Minchir es-schudscha in Bode's large star atlas, Uranographia. The name which derived from the Arabic appelationمنخر الشجاع minkhar ash-shujāʽ "the nostril brave one" (the hydra) for this star. The name is erroneously[citation needed] spelt as Al Minliar al Shuja in the Yale Bright Star Catalogue.[12] In 2016, the IAU organized a Working Group on Star Names (WGSN)[13] to catalog and standardize proper names for stars. The WGSN approved the name Minchir for this star on 5 September 2017 and it is now so included in the List of IAU-approved Star Names.[10]

This star, along with Delta Hydrae (Lisan al Shudja), Epsilon Hydrae, Zeta Hydrae, Eta Hydrae and Rho Hydrae, were Ulug Beg's Min al Azʽal, "Belonging to the Uninhabited Spot".[14] (According to a 1971 NASA memorandum, Min al Azʽal or Minazal were the title for five stars : Delta Hydrae as Minazal I, Eta Hydrae as Minazal II, Epsilon Hydrae as Minazal III, Rho Hydrae as Minazal IV and Zeta Hydrae as Minazal V.[15])

In Chinese, 柳宿 (Liǔ Sù), meaning Willow (asterism), refers to an asterism consisting of Sigma Hydrae, Delta Hydrae, Eta Hydrae, Rho Hydrae, Epsilon Hydrae, Zeta Hydrae, Omega Hydrae and Theta Hydrae.[16] Consequently, Sigma Hydrae itself is known as 柳宿二 (Liǔ Sù èr, English: the Second Star of Willow).[17]

The people of Groote Eylandt, used the name Unwala ("The Crab") for the star cluster including this star, Delta Hydrae (Lisan al Shudja), Epsilon Hydrae, Zeta Hydrae, Eta Hydrae and Rho Hydrae.[18]

Properties

This is an evolved K-type giant star with a stellar classification of K2 III.[3] The measured angular diameter of this star, after correction for limb darkening, is 2.25±0.03 mas.[19] At its estimated distance, this yields a physical size of about 27.6 times the radius of the Sun.[7] It has about three times the mass of the Sun and radiates 295 times the solar luminosity from its outer atmosphere at an effective temperature of 4,491 K. Sigma Hydrae is around 430 million years old.[6]

References

  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)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
  3. ^ a b Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
  4. ^ a b Famaey, B.; et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430 (1): 165–186, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272, S2CID 17804304
  5. ^ 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 Luck, R. Earle (September 2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 23, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114, 88.
  7. ^ a b Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R*) is given by:
     
  8. ^ a b Prugniel, Ph.; et al. (July 2011), "The atmospheric parameters and spectral interpolator for the MILES stars", Astronomy & Astrophysics, 531: A165, arXiv:1104.4952, Bibcode:2011A&A...531A.165P, doi:10.1051/0004-6361/201116769, S2CID 54940439.
  9. ^ "* sig Hya". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-01-08.{{cite web}}: CS1 maint: postscript (link)
  10. ^ a b "Naming Stars". IAU.org. Retrieved 16 December 2017.
  11. ^ 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.
  12. ^ "VizieR Service".
  13. ^ "IAU Working Group on Star Names (WGSN)". Retrieved 22 May 2016.
  14. ^ Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York, NY: Dover Publications Inc. p. 249. ISBN 0-486-21079-0. Retrieved 2010-12-12.
  15. ^ Rhoads, Jack W. (November 15, 1971), Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars (PDF), Jet Propulsion Laboratory, California Institute of Technology, retrieved 2017-01-09.
  16. ^ (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.
  17. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 28 日
  18. ^ Selin, Helaine, ed. (1997), Encyclopaedia of the history of science, technology, and medicine in non-western cultures, Dordrecht: Kluwer Academic Publishers, p. 105, ISBN 9780792340669.
  19. ^ Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.

January 06, 2023
sigma, hydrae, hydrae, abbreviated, sigma, also, named, minchir, solitary, star, equatorial, constellation, hydra, visible, naked, with, apparent, visual, magnitude, estimated, distance, this, star, from, based, upon, annual, parallax, shift, around, light, ye. Sigma Hydrae s Hydrae abbreviated Sigma Hya s Hya also named Minchir ˈ m ɪ ŋ k er 10 is a solitary 11 star in the equatorial constellation of Hydra It is visible to the naked eye with an apparent visual magnitude of 4 48 2 The estimated distance to this star from the Sun based upon an annual parallax shift of 8 75 mas 1 is around 370 light years At that distance the visual magnitude of the star is diminished by an interstellar extinction factor of 0 16 4 due to intervening dust Sigma Hydrae Observation dataEpoch J2000 0 Equinox J2000 0 ICRS Constellation HydraRight ascension 08h 38m 45 43747s 1 Declination 03 20 29 1701 1 Apparent magnitude V 4 48 2 CharacteristicsSpectral type K2 III 3 U B color index 1 23 2 B V color index 1 21 2 AstrometryRadial velocity Rv 27 28 0 19 4 km sProper motion m RA 19 48 1 mas yr Dec 15 92 1 mas yrParallax p 8 75 0 25 mas 1 Distance370 10 ly 114 3 pc Absolute magnitude MV 0 84 5 Details 6 Mass3 07 M Radius27 6 7 R Luminosity295 L Surface gravity log g 2 21 0 13 8 cgsTemperature4 491 51 KMetallicity Fe H 0 13 0 06 8 dexAge430 MyrOther designationss Hya 5 Hydrae BD 03 2026 FK5 1224 HD 73471 HIP 42402 HR 3418 SAO 116988 9 Database referencesSIMBADdataNomenclature Edits Hydrae Latinised to Sigma Hydrae is the system s Bayer designation It bore the traditional name Minchir appearing as Minchir es schudscha in Bode s large star atlas Uranographia The name which derived from the Arabic appelationمنخر الشجاع minkhar ash shujaʽ the nostril brave one the hydra for this star The name is erroneously citation needed spelt as Al Minliar al Shuja in the Yale Bright Star Catalogue 12 In 2016 the IAU organized a Working Group on Star Names WGSN 13 to catalog and standardize proper names for stars The WGSN approved the name Minchir for this star on 5 September 2017 and it is now so included in the List of IAU approved Star Names 10 This star along with Delta Hydrae Lisan al Shudja Epsilon Hydrae Zeta Hydrae Eta Hydrae and Rho Hydrae were Ulug Beg s Min al Azʽal Belonging to the Uninhabited Spot 14 According to a 1971 NASA memorandum Min al Azʽal or Minazal were the title for five stars Delta Hydrae as Minazal I Eta Hydrae as Minazal II Epsilon Hydrae as Minazal III Rho Hydrae as Minazal IV and Zeta Hydrae as Minazal V 15 In Chinese 柳宿 Liǔ Su meaning Willow asterism refers to an asterism consisting of Sigma Hydrae Delta Hydrae Eta Hydrae Rho Hydrae Epsilon Hydrae Zeta Hydrae Omega Hydrae and Theta Hydrae 16 Consequently Sigma Hydrae itself is known as 柳宿二 Liǔ Su er English the Second Star of Willow 17 The people of Groote Eylandt used the name Unwala The Crab for the star cluster including this star Delta Hydrae Lisan al Shudja Epsilon Hydrae Zeta Hydrae Eta Hydrae and Rho Hydrae 18 Properties EditThis is an evolved K type giant star with a stellar classification of K2 III 3 The measured angular diameter of this star after correction for limb darkening is 2 25 0 03 mas 19 At its estimated distance this yields a physical size of about 27 6 times the radius of the Sun 7 It has about three times the mass of the Sun and radiates 295 times the solar luminosity from its outer atmosphere at an effective temperature of 4 491 K Sigma Hydrae is around 430 million years old 6 References Edit 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 amp A 474 653V doi 10 1051 0004 6361 20078357 S2CID 18759600 a b c d Mermilliod J C 1986 Compilation of Eggen s UBV data transformed to UBV unpublished Catalogue of Eggen s UBV Data SIMBAD Bibcode 1986EgUBV 0M a b Houk N Swift C 1999 Michigan catalogue of two dimensional spectral types for the HD Stars Michigan Spectral Survey 5 Bibcode 1999MSS C05 0H a b Famaey B et al January 2005 Local kinematics of K and M giants from CORAVEL Hipparcos Tycho 2 data Revisiting the concept of superclusters Astronomy and Astrophysics 430 1 165 186 arXiv astro ph 0409579 Bibcode 2005A amp A 430 165F doi 10 1051 0004 6361 20041272 S2CID 17804304 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 a b Luck R Earle September 2015 Abundances in the Local Region I G and K Giants The Astronomical Journal 150 3 23 arXiv 1507 01466 Bibcode 2015AJ 150 88L doi 10 1088 0004 6256 150 3 88 S2CID 118505114 88 a b Lang Kenneth R 2006 Astrophysical formulae Astronomy and astrophysics library vol 1 3rd ed Birkhauser ISBN 3 540 29692 1 The radius R is given by 2 R 114 2 25 10 3 AU 0 0046491 AU R 55 2 R displaystyle begin aligned 2 cdot R amp frac 114 cdot 2 25 cdot 10 3 text AU 0 0046491 text AU R bigodot amp approx 55 2 cdot R bigodot end aligned a b Prugniel Ph et al July 2011 The atmospheric parameters and spectral interpolator for the MILES stars Astronomy amp Astrophysics 531 A165 arXiv 1104 4952 Bibcode 2011A amp A 531A 165P doi 10 1051 0004 6361 201116769 S2CID 54940439 sig Hya SIMBAD Centre de donnees astronomiques de Strasbourg Retrieved 2017 01 08 a href Template Cite web html title Template Cite web cite web a CS1 maint postscript link a b Naming Stars IAU org Retrieved 16 December 2017 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 VizieR Service IAU Working Group on Star Names WGSN Retrieved 22 May 2016 Allen R H 1963 Star Names Their Lore and Meaning Reprint ed New York NY Dover Publications Inc p 249 ISBN 0 486 21079 0 Retrieved 2010 12 12 Rhoads Jack W November 15 1971 Technical Memorandum 33 507 A Reduced Star Catalog Containing 537 Named Stars PDF Jet Propulsion Laboratory California Institute of Technology retrieved 2017 01 09 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 in Chinese AEEA Activities of Exhibition and Education in Astronomy 天文教育資訊網 2006 年 5 月 28 日 Selin Helaine ed 1997 Encyclopaedia of the history of science technology and medicine in non western cultures Dordrecht Kluwer Academic Publishers p 105 ISBN 9780792340669 Richichi A et al February 2005 CHARM2 An updated Catalog of High Angular Resolution Measurements Astronomy and Astrophysics 431 2 773 777 Bibcode 2005A amp A 431 773R doi 10 1051 0004 6361 20042039 Retrieved from https en wikipedia org w index php title Sigma Hydrae amp oldid 1122157260, wikipedia, wiki, book, books, library,

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