Although Beta Herculis appears to the naked eye to be a single star, in July 1899 the American astronomer
W. W. Campbell discovered from spectroscopic measurements that its
radial velocity varies, and concluded that it has a companion.[15]
Properties
At
Palomar Observatory,
Antoine Labeyrie and others used
speckle interferometry with the
Hale Telescope to resolve the system in 1977.[16] The
Hipparcos satellite observed the orbital motion of the primary relative to other stars,[17] and an orbit was computed in 2005 using spectroscopic data together with these measurements. The period of the system is around 410 days. They have a high
orbital eccentricity of 0.55 and the orbital plane is inclined 53.8° to the line of sight from the
Earth.[9]
The primary star has a
stellar classification of G7 IIIa,[3] indicating that it is a
giant star that has exhausted the hydrogen at its core and evolved away from the
main sequence. It has a mass nearly three times the
mass of the Sun, and has expanded to 17 times the
Sun's radius.[8] The
effective temperature of the star's outer envelope is about 4,887 K,[8] which gives it the yellow hue of a G-type star.[18] The secondary star has a mass only 90% that of the Sun.[3]
It bore the traditional names Kornephoros, a
Greek word meaning "club bearer", and Rutilicus, a corruption of the
Latin word titillicus, meaning "armpit". In 2016, the
International Astronomical Union organized a
Working Group on Star Names (WGSN)[19] to catalogue and standardize proper names for stars. The WGSN approved the name Kornephoros for this star on 21 August 2016 and it is now so entered in the IAU Catalog of Star Names.[12]
It was a member of the indigenous
Arabicasterismal-Nasaq al-Shāmī, "the Northern Line" of al-Nasaqān "the Two Lines",[20] along with
Gamma Herculis,
Gamma Serpentis and
Beta Serpentis.[21] Though, according to a 1971
NASA catalog, al-Nasaq al-Sha'āmī or Nasak Shamiya was the title for three other stars: Beta Serpentis as Nasak Shamiya I, Gamma Serpentis as Nasak Shamiya II and Gamma Herculis as Nasak Shamiya III.[22]
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 which is marking the right borderline of the enclosure, consisting of Beta Herculis, Gamma Herculis,
Kappa Herculis, Gamma Serpentis, Beta Serpentis,
Delta Serpentis,
Alpha Serpentis,
Epsilon Serpentis,
Delta Ophiuchi,
Epsilon Ophiuchi and
Zeta Ophiuchi.[23] Consequently, the
Chinese name for Beta Herculis itself is 天市右垣一 (Tiān Shì Zuǒ Yòu yī, English: the First Star of Right Wall of Heavenly Market Enclosure), represent Hézhōng (河中), possibly Hezhong Municipality or Hezhong Circuit (see :
Wang Chongrong, formally the Prince of Langye 瑯琊王, was a warlord of the late Chinese
Tang dynasty who controlled Hezhong Circuit, headquartered in modern
Yuncheng, Shanxi).[24][25]Hézhōng (河中) was westernized into Ho Chung by R.H. Allen, which means "in the river".[26]
^
abHR 6148, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr.,
CDS ID
V/50. Accessed on line September 18, 2008.
^Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Carnegie Institute of Washington, D.C.,
Bibcode:
1953GCRV..C......0W
^
abPan, X. P.; et al. (September 1990), "The Visual Orbit, the Stellar Diameter and the Magnitude Difference of the Spectroscopic Binary β Herculis", Bulletin of the American Astronomical Society, 22: 1335,
Bibcode:
1990BAAS...22R1335P
^Blazit, A.; Bonneau, D.; Koechlin, L.; Labeyrie, A. (June 1, 1977), "The digital speckle interferometer: preliminary results on 59 stars and 3C 27", Astrophysical Journal Letters, 214: L79–L84,
Bibcode:
1977ApJ...214L..79B,
doi:
10.1086/182447
^HIP 80816, database entry, The Hipparcos and Tycho Catalogues, ESA, 1997,
CDS ID
I/239.
^"The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from
the original on 2012-03-18, retrieved 2012-01-16
^Kunitzsch, P., Smart, T. (2006), A Dictionary of Modern Star names: A Short Guide to 254 Star names and Their Derivations (Second Revised ed.), Cambridge, Massachusetts: Sky Publishing, p. 31,
ISBN1-931559-44-9{{
citation}}: CS1 maint: multiple names: authors list (
link)