Omega Herculis

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Template:Short description Template:About-distinguish

Omega Herculis
File:Hercules Historical View.png
Historical view of the Hercules constellation showing the star Kajam (ω Her) as "the club" in the hero's right hand.
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Hercules[1]
Right ascension Template:RA[2]
Declination Template:DEC[2]
Apparent magnitude (V) 4.5821[2] (4.58 + 11.5)[3]
Characteristics
Spectral type A2 Vp CrSr[4]
U−B Template:Engvar +0.01[5]
B−V Template:Engvar +0.00[5]
Variable type α2 CVn[6]
Astrometry
Radial velocity (Rv)Script error: No such module "val".[7] km/s
Proper motion (μ) RA: +40.86[2] mas/yr
Dec.: −59.71[2] mas/yr
Parallax (π)13.04±0.64 mas[2]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)Script error: No such module "val".[8]
Details
ω Her A
Mass2.14[9] Template:Solar mass
Radius3.30[10] Template:Solar radius
Luminosity70[11] Template:Solar luminosity
Surface gravity (log g)Script error: No such module "val".[12] cgs
TemperatureScript error: No such module "val".[12] K
Metallicity [Fe/H]Script error: No such module "val".[12] dex
Rotation2.951[13] d
Rotational velocity (v sin i)55[14] km/s
Age149[9] Myr
Metallicity [Fe/H]{{{metal_fe2}}} dex
Other designations
Cujam, ω Her, 24 Her, 51 Ser, BD+14°3049, FK5 613, HD 148112, HIP 80463, HR 6117, SAO 102153, WDS J16254+1402AB[15]
Database references
SIMBADdata

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Omega Herculis (ω Herculis, abbreviated Ome Her, ω Her) is a binary star[3] system in the northern constellation of Hercules. Based upon an annual parallax shift of 13.04 mas as seen from Earth, it is located around 250 light-years from the Sun. It is faintly visible to the naked eye, having a combined apparent visual magnitude of 4.58.[2] The system is a candidate for membership in the Ursa Major Moving Group, although this remains uncertain.[8]

The two components are designated Omega Herculis A (officially named Cujam Template:IPAc-en, the traditional name of the system)[16] and B.

Nomenclature

ω Herculis (Latinised to Omega Herculis) is the system's Bayer designation. It previously bore the Flamsteed designation of 51 Serpentis before being added to Hercules.[17] The designations of the two components as Omega Herculis A and B derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).[18]

The system bore the traditional name Cujam (also written as Cajam and Kajam), meaning ("club").[19] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[20][21] to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.[22] It approved the name Cujam for the component Omega Herculis A on February 1, 2017 and it is now so included in the List of IAU-approved Star Names.[16]

In Chinese, Script error: No such module "Lang". (Script error: No such module "Lang".), meaning Dipper for Liquid, refers to an asterism consisting of Omega Herculis, 49 Serpentis, 13 Herculis, 29 Herculis and 33 Herculis.[23] Consequently, the Chinese name for Omega Herculis itself is Script error: No such module "Lang". (Script error: No such module "Lang"., Template:Langx).[24]

Properties

The primary, Omega Herculis A, is a chemically peculiar Ap star with a stellar classification of A2 Vp CrSr.[4] The spectrum displays abnormally strong absorption lines of chromium and strontium, and weak lines of calcium and magnesium.[4] An A-type star, it has an estimated 2.14[9] times the mass of the Sun and 3.30[10] times the Sun's radius. The star is around 149[9] million years old and is radiating 70[11] times the solar luminosity from its photosphere at an effective temperature of 10,052 K.[12]

This component is an Alpha2 Canum Venaticorum variable[6] with a brightness amplitude of 0.4 magnitude and a 2.951 day phase that presumably matches the rotation period. The pattern of variation shows that there are regions of the star's surface where the concentrations of elements differ. The star also displays short period variations on the order of 2.5 hours.[13] It has a mean effective magnetic field value of Script error: No such module "val"..[25]

The secondary, Omega Herculis B, is a magnitude 11.5 companion star.[3] As of 2010, it was located at an angular separation of 0.80 arc seconds along a position angle of 294°.[26]

References

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  1. ↑ Template:Cite constellation
  2. ↑ a b c d e f g Script error: No such module "citation/CS1".
  3. ↑ a b c Script error: No such module "citation/CS1".
  4. ↑ a b c Script error: No such module "citation/CS1".
  5. ↑ a b Script error: No such module "citation/CS1".
  6. ↑ a b Script error: No such module "citation/CS1".
  7. ↑ Script error: No such module "citation/CS1".
  8. ↑ a b Script error: No such module "citation/CS1".
  9. ↑ a b c d Script error: No such module "citation/CS1".
  10. ↑ a b Script error: No such module "citation/CS1".
  11. ↑ a b Script error: No such module "citation/CS1".
  12. ↑ a b c d Script error: No such module "citation/CS1".
  13. ↑ a b Script error: No such module "citation/CS1".
  14. ↑ Script error: No such module "citation/CS1".
  15. ↑ Template:Cite simbad
  16. ↑ a b Script error: No such module "citation/CS1".
  17. ↑ Script error: No such module "citation/CS1".
  18. ↑ Script error: No such module "citation/CS1".
  19. ↑ Script error: No such module "citation/CS1".
  20. ↑ Script error: No such module "citation/CS1".
  21. ↑ Script error: No such module "citation/CS1".
  22. ↑ Script error: No such module "citation/CS1".
  23. ↑ Template:In lang 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, Template:ISBN.
  24. ↑ Template:In lang 香港太空館 - 研究資源 - 亮星中英對照表 Template:Webarchive, Hong Kong Space Museum. Accessed on line November 23, 2010.
  25. ↑ Script error: No such module "citation/CS1".
  26. ↑ Script error: No such module "citation/CS1".

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Template:Stars of Hercules

Template:Sky

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