Lambda Herculis

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Lambda Herculis
Observation data
Epoch J2000      Equinox J2000
Constellation Hercules
Right ascension 17h 30m 44.3099s[1]
Declination +26° 06′ 38.323″[1]
Apparent magnitude (V) 4.402[2]
Spectral type K4III[2]
U−B color index +1.68[3]
B−V color index +1.44[3]
Radial velocity (Rv) −26.51[4] km/s
Proper motion (μ) RA: +18.39[1] mas/yr
Dec.: +16.78[1] mas/yr
Parallax (π) 8.88 ± 0.64[1] mas
Distance 370 ± 30 ly
(113 ± 8 pc)
Surface gravity (log g) 1.89[5] cgs
Temperature 4,070[5] K
Metallicity \begin{smallmatrix}\left[\frac{Fe}{H}\right]\ =\ -0.04\end{smallmatrix}[5]
Rotational velocity (v sin i) 8[6] km/s
Other designations
76 Her, HR 6526, BD+26 3034, HD 158899, SAO 85163, FK5 1460, HIP 85693.[2]

Lambda Herculis (λ Her, λ Herculis) is a star in the constellation Hercules. It has the traditional name Maasym ("wrist").

In Chinese, 天市左垣 (Tiān Shì Zuǒ Yuán), meaning Left Wall of Heavenly Market Enclosure, refers to an asterism which is represent eleven old states in China which is marking the left borderline of the enclosure, consisting of λ Herculis, δ Herculis, μ Herculis, ο Herculis, 112 Herculis, ζ Aquilae, θ1 Serpentis, η Serpentis, ν Ophiuchi, ξ Serpentis and η Ophiuchi.[7] Consequently, λ Herculis itself is known as 天市左垣二 (Tiān Shì Zuǒ Yuán èr, English: the Second Star of Left Wall of Heavenly Market Enclosure), represent the state Zhao (or Chaou (趙)).,[8][9] together with 26 Capricorni and 27 Capricorni ("m Capricorni" in R.H.Allen version[10]) in Twelve States (asterism).


Lambda Herculis belongs to spectral class K3.5III and has apparent magnitude +4.4. It is approximately 370 light years from Earth.

In 1783, English astronomer William Herschel found that the Solar System is, as a whole, moving in a direction close to the position in the sky of Lambda Herculis.[11]


  1. ^ a b c d e Perryman, M. A. C.; et al. (1997), "The Hipparcos Catalogue", Astronomy & Astrophysics 323: L49–L52, Bibcode:1997A&A...323L..49P 
  2. ^ a b c "lam Her -- Variable Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2010-07-03. 
  3. ^ a b Johnson, H. L.; Iriarte, B.; Mitchell, R. I.; Wisniewskj, W. Z. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory 4 (99). Bibcode:1966CoLPL...4...99J. 
  4. ^ Famaey, B.; Jorissen, A.; Luri, X.; Mayor, M.; Udry, S.; Dejonghe, H.; Turon, C. (January 2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics 430: 165–186. arXiv:astro-ph/0409579. Bibcode:2005A&A...430..165F. doi:10.1051/0004-6361:20041272. 
  5. ^ a b c McWilliam, Andrew (December 1990). "High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances". Astrophysical Journal Supplement Series 74: 1075–1128. Bibcode:1990ApJS...74.1075M. doi:10.1086/191527. 
  6. ^ Bernacca, P. L.; Perinotto, M. (1970). "A catalogue of stellar rotational velocities". Contributi Osservatorio Astronomico di Padova in Asiago 239 (1). Bibcode:1970CoAsi.239....1B. 
  7. ^ (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.
  8. ^ (Chinese) 香港太空館 - 研究資源 - 亮星中英對照表, Hong Kong Space Museum. Accessed on line November 23, 2010.
  9. ^ (Chinese) English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name, Hong Kong Space Museum. Accessed on line November 23, 2010.
  10. ^ Star Names - R.H.Allen p.142
  11. ^ Lankford, John (1997). History of astronomy: an encyclopedia. Garland encyclopedias in the history of science 1. Taylor & Francis. p. 258. ISBN 0-8153-0322-X.