Kappa Herculis

κ Herculis

Historical view of the Hercules constellation showing Marfik (κ Her) as the hero's left "elbow".
Observation data
Epoch J2000      Equinox J2000
Constellation Hercules
κ Her A
Right ascension 16h 08m 04.52481s[1]
Declination 17° 02′ 49.1150″[1]
Apparent magnitude (V) 4.994[2]
κ Her B
Right ascension 16h 08m 04.95406s[3]
Declination 17° 03′ 15.6853″[3]
Apparent magnitude (V) 6.25[4]
Characteristics
Spectral type G7III + K0IV[5]
U−B color index +0.630
B−V color index +0.931
Variable type suspected[6]
Astrometry
κ Her A
Radial velocity (Rv)−10.50[7] km/s
Proper motion (μ) RA: -35.55[1] mas/yr
Dec.: -7.04[1] mas/yr
Parallax (π)8.87 ± 0.55[1] mas
Distance370 ± 20 ly
(113 ± 7 pc)
Absolute magnitude (MV)−0.25[8]
κ Her B
Radial velocity (Rv)+32.21[9] km/s
Proper motion (μ) RA: -25.70[3] mas/yr
Dec.: -39.45[3] mas/yr
Parallax (π)1.55 ± 1.98[3] mas
Distanceapprox. 2,000 ly
(approx. 600 pc)
Details
κ Her A
Mass3.4[10] M☉
Radius~16[11] R☉
Luminosity144[8] L☉
Temperature4,990[12] K
Metallicity [Fe/H]−0.26[12] dex
Rotational velocity (v sin i)10[13] km/s
Age~400[11] Myr
Other designations
Marsic, κ Her, 7 Her, CCDM J16081+1703, NSV 7471, AAVSO 1603+17, WDS 16081+1703
A: HR 6008, HD 145001, HIP 79043, BD +77°2964
B: HR 6009, HD 145000, HIP 79045, BD +77°2965
Database references
SIMBADκ Her
κ Her A
κ Her B

Coordinates: 16h 08m 04.526s, +17° 02′ 49.13″

Kappa Herculis (κ Herculis, abbreviated Kap Her, κ Her) is a double star in the constellation of Hercules. The two components, Kappa Herculis A (also named Marsic[14]) and B, were 27.3 arc seconds apart in 2000, but are not physically related. Based on parallax measurements from the Hipparcos mission, κ Her A is about 113 parsecs (370 light-years) from the Sun and κ Her B is 600 parsecs (2,000 light-years).

A faint third component Kappa Herculis C is just over 1 arc-minute away.[15] The star 8 Herculis forms a naked-eye pair with Kappa Herculis.

Nomenclature

κ Herculis (Latinised to Kappa Herculis) is the system's Bayer designation. The designations of the components as Kappa Herculis A, B and C derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).[16]

The system bore the traditional names of "Marsic", "Marfik" or "Marfak", all of which come from the Arabic لمرفق Al-Mirfaq meaning "the elbow",[17] a name (or some derivative of which) it shared with Lambda Ophiuchi. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[18] to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.[19] It approved the name Marsic for the component Kappa Herculis A on February 1, 2017, and Marfik for the primary component of Lambda Ophiuchi on September 12, 2016, and they are both now so included in the List of IAU-approved Star Names.[14]

In Chinese, 天市右垣 (Tiān Shì Yòu Yuán), meaning Right Wall of Heavenly Market Enclosure, refers to an asterism which represents eleven old states in China and marks the right borderline of the enclosure, consisting of Kappa Herculis, Beta Herculis, Gamma Herculis, Gamma Serpentis, Beta Serpentis, Delta Serpentis, Alpha Serpentis, Epsilon Serpentis, Delta Ophiuchi, Epsilon Ophiuchi and Zeta Ophiuchi.[20] Consequently, Kappa Herculis itself is known as 天市右垣三 (Tiān Shì Yòu Yuán sān, English: the Third Star of Right Wall of Heavenly Market Enclosure), representing the state of Jin (晉) (or Tsin),[21][22] together with 36 Capricorni in Twelve States (asterism).[23]

Properties

Kappa Herculis A is a giant star with stellar classification G8III. With a mass of 3.0 M☉ and radius that is 16 R☉, the star boasts a total bolometric luminosity that is 150 L☉.[11]

Kappa Herculis is a suspected variable star with a reported magnitude range of 4.70 to 5.02.[6]

References

  1. 1 2 3 4 5 van Leeuwen, F (November 2007). "Hipparcos, the New Reduction". Astronomy and Astrophysics. Centre de Données astronomiques de Strasbourg. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Retrieved 2010-09-26.
  2. ↑ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27. Bibcode:2000A&A...355L..27H.
  3. 1 2 3 4 5 van Leeuwen, F (November 2007). "Hipparcos, the New Reduction". Astronomy and Astrophysics. Centre de Données astronomiques de Strasbourg. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Retrieved 2010-09-26.
  4. ↑ Argue, A. N. (1963). "UBV photometry of 300 G and K type stars". Monthly Notices of the Royal Astronomical Society. 125 (6): 557. Bibcode:1963MNRAS.125..557A. doi:10.1093/mnras/125.6.557.
  5. ↑ Abt, H. A. (1981). "Visual multiples. VII - MK classifications". Astrophysical Journal Supplement Series. 45: 437. Bibcode:1981ApJS...45..437A. doi:10.1086/190719.
  6. 1 2 Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/gcvs. Originally published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
  7. ↑ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065.
  8. 1 2 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.
  9. ↑ Famaey, B.; Jorissen, A.; Luri, X.; Mayor, M.; Udry, S.; Dejonghe, H.; Turon, C. (2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics. 430: 165. arXiv:astro-ph/0409579. Bibcode:2005A&A...430..165F. doi:10.1051/0004-6361:20041272.
  10. ↑ Gondoin, P. (December 1999), "Evolution of X-ray activity and rotation on G-K giants", Astronomy and Astrophysics, 352: 217–227, Bibcode:1999A&A...352..217G
  11. 1 2 3 Kaler, James B. "MARSIC (Kappa Herculis)". University of Illinois. Retrieved 2010-09-26.
  12. 1 2 McWilliam, Andrew (December 1990). "High-resolution spectroscopic survey of 671 GK giants". Astrophysical Journal Supplement Series. 74: 1075–1128. Bibcode:1990ApJS...74.1075M. doi:10.1086/191527. ISSN 0067-0049.
  13. ↑ "Bright Star Catalogue (Hoffleit+, 1991)". VizieR (5th Revised ed.). Centre de Données astronomiques de Strasbourg. Retrieved 2010-09-26.
  14. 1 2 "Naming Stars". IAU.org. Retrieved 16 December 2017.
  15. ↑ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (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.
  16. ↑ Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv:1012.0707 [astro-ph.SR].
  17. ↑ Kurt Vonnegut. "Constellations: Hercules 'the Strongman'". The BBC (British Broadcasting Corporation). Retrieved 2010-11-14.
  18. ↑ "International Astronomical Union | IAU". www.iau.org. Retrieved 2017-04-01.
  19. ↑ "WG Triennial Report (2015-2018) - Star Names" (PDF). p. 5. Retrieved 2018-07-14.
  20. ↑ (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.
  21. ↑ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 Archived 2011-01-30 at the Wayback Machine., Hong Kong Space Museum. Accessed on line November 23, 2010.
  22. ↑ (in Chinese) English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name Archived 2008-09-24 at the Wayback Machine., Hong Kong Space Museum. Accessed on line November 23, 2010.
  23. ↑ Star Names - R.H.Allen p.142
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