Zeta Herculis Moving Group is a set of stars that share a common motion through space.

The existence of this moving group was first published in 1958 by Olin J. Eggen. Based upon the high velocity motion of the star Zeta Herculis through space, he searched for stars that were following a similar velocity and direction. A total of 22 candidate members were identified. Among the group members he included β Hydri, ρ Persei, η Reticuli, φ1 Lupi, ζ Herculis and ε Octantis. He estimated the group velocity at 74.5 km/s.[1] In 1970, Richard Woolley refined the list to ten stars, including φ2 Pavonis and ζ1/ζ2 Reticuli as members of this cluster.[2]

The parallel motion of the stars in this group implies a common origin, and hence a similar age and composition. The membership of ζ Herculis and HD 158614 came into question because their composition appeared to show they were much younger than other members of the group. The average age was estimated as 8.2 × 109 years, while ζ Herculis was estimated as 6.3 billion years in age.[3] However, a statistical analysis of the metallicity for stars in this group showed no difference from a comparison sample, indicating that it may not be possible to determine more information about this group based on the composition of its members.[4]

Members of the ζ Her moving group (1958 version)[1]
Name Constellation B F HD HIP vis.
mag.		 Dist. (ly) Sp. class Notes
ζ HerHerculesζ40150680816932.8135F9IV
β HyiHydrusβ215120212.8224G2IV
ρ PerPerseusρ2519058143543.32325M3IIIvarGorgonea Tertia
φ1 LupLupusφ188136422751773.57326K5III
47 PscPisces47241122195.01490M3IIIvarTV Psc
ε OctOctansε2109671102565.09268M6IIIBO Oct
η RetReticulumη28093203845.24380G7III
84 VirVirgo84119425669365.35217K1III
HD 71377Puppis71377413955.52268K1/K2III
HD 43899Columba43899298425.54302K2III
HD 100733CentaurusC1100733565185.64652M3IIIV763 Cen
HD 150275Ursa Minor150275808506.35408K1III
29 LMiLeo Minor2990250510476.49413K1III
HD 221354Cassiopeia2213541160856.7655K2VGliese 895.4
HD 9166Cassiopeia916671666.81485K3III
HD 30455Taurus30455223496.96100G2V...
71 LeoLeo7198824555337.03773K1III
HD 219829Cassiopeia2198291151128.09106K0V...
HD 68788Camelopardalis68788408488.35101K1V
HD 209134Pisces Austrinus2091349.11K3V
HD 89668Sextans89668506579.42106F8V
HD 106364Camelopardalis10636410.03K2III+...
Members of the ζ her moving group (1970 version)[2]
Name Constellation B F HD HIP vis.
mag.		 Dist. (ly) Sp. class Notes
ζ HerHerculesζ40150680816932.8135F9IV
β HyiHydrusβ215120212.8224G2IV
φ2 PavPavoφ21963781019835.1179F8V
ζ2 RetReticulumζ220807153715.2439G1V
HD 158614Ophiuchus158614856675.3154G8IV-VGliese 678
ζ1 RetReticulumζ120766153305.5340G2V
1 HyaHydra170958412115.6189F3V
HD 14680Fornax14680109778.79100F3V
HIP 59198Virgo5919811.6994K7Gliese 456

References

  1. 1 2 Eggen, O. J. (1958). "Stellar groups. II. The ζ Herculis, ε Indi and 61 Cygni groups of high-velocity stars". Monthly Notices of the Royal Astronomical Society. 118 (2): 154–. Bibcode:1958MNRAS.118..154E. doi:10.1093/mnras/118.2.154.
  2. 1 2 Woolley, Richard van der Reit (1970). "Box Orbits of Nearby Stars". Galactic Astronomy: Proceedings. Gordon and Breach. pp. 95–160.
  3. ↑ Porto de Mello, G. F.; da Silva, L. (November 1991). "On the physical existence of the Zeta HER moving group - A detailed analysis of Phi exp 2 Pavonis". Astronomical Journal. 102: 1816–1825. Bibcode:1991AJ....102.1816P. doi:10.1086/116006.
  4. ↑ Taylor, B. J. (2000). "A statistical analysis of the metallicities of nine old superclusters and moving groups". Astronomy and Astrophysics. 362: 563–579. Bibcode:2000A&A...362..563T.
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