Mu Aquarii

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Mu Aquarii
Diagram showing star positions and boundaries of the Aquarius constellation and its surroundings
Cercle rouge 100%.svg

Location of μ Aquarii (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Aquarius
Right ascension 20h 52m 39.23277s[1]
Declination −08° 58′ 59.9499″[1]
Apparent magnitude (V) 4.731[2]
Spectral type A3m[3]
U−B color index +0.149[2]
B−V color index +0.322[2]
Radial velocity (Rv) −9.1[4] km/s
Proper motion (μ) RA: +45.75[1] mas/yr
Dec.: -33.59[1] mas/yr
Parallax (π) 20.74 ± 0.29[1] mas
Distance 157 ± 2 ly
(48.2 ± 0.7 pc)
Surface gravity (log g) 3.99[5] cgs
Temperature 7,181[5] K
Rotational velocity (v sin i) 53.7[5] km/s
Other designations
6 Aquarii, BD−09 5598, FK5 1547, HD 198743, HIP 103045, HR 7990, SAO 144895.[6]
Database references

Mu Aquarii (μ Aqr, μ Aquarii) is the Bayer designation for a binary star[7] in the equatorial constellation of Aquarius. It is visible to the naked eye with an apparent magnitude of 4.7.[2] Based upon parallax measurements, the distance to this system is about 157 light-years (48 parsecs).[1] Mu Aquarii is a spectroscopic binary system with an orbital period of 1,566 days and an eccentricity of 0.23.[8] The combined spectrum matches a stellar classification of A3m, with the 'm' suffix indicating that this is an Am, or chemically peculiar star.[3]

This star together with ν Aquarii is Albulaan, derived from an Arabic term al-bulacān (ألبولعان) meaning "the two swallowers". This star, along with ε Aqr (Albali) and ν Aqr (Albulaan), were al Bulaʽ (البلع), the Swallower.[9][10] In Chinese, 奎宿 (Nǚ Sù), meaning Girl (asterism) (or Woman), refers to an asterism consisting of μ Aquarii, ε Aquarii, 4 Aquarii, 5 Aquarii and 3 Aquarii.[11] Consequently, μ Aquarii itself is known as 奎宿二 (Nǚ Sù èr, English: the Second Star of Girl / Woman.)[12]


  1. ^ a b c d e f van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752Freely accessible, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d Gutierrez-Moreno, Adelina; et al. (1966), A System of photometric standards, 1, Publicaciones Universidad de Chile, Department de Astronomy, pp. 1–17, Bibcode:1966PDAUC...1....1G. 
  3. ^ a b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819. 
  4. ^ Wilson, Ralph Elmer (1953). General Catalogue of Stellar Radial Velocities. Washington: Carnegie Institution of Washington. Bibcode:1953GCRV..C......0W. 
  5. ^ a b c Schröder, C.; Reiners, A.; Schmitt, J. H. M. M. (January 2009). "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo". Astronomy and Astrophysics. 493 (3): 1099–1107. Bibcode:2009A&A...493.1099S. doi:10.1051/0004-6361:200810377. 
  6. ^ "6 Aqr -- Star", SIMBAD Astronomical Object Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-07-01. 
  7. ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, Bibcode:2008MNRAS.389..869E, arXiv:0806.2878Freely accessible, doi:10.1111/j.1365-2966.2008.13596.x. 
  8. ^ Abt, Helmut A. (August 2005), "Observed Orbital Eccentricities", The Astrophysical Journal, 629 (1): 507–511, Bibcode:2005ApJ...629..507A, doi:10.1086/431207. 
  9. ^ Davis Jr., G. A. (October 1944), "The Pronunciations, Derivations, and Meanings of a Selected List of Star Names", Popular Astronomy, 52 (3): 12, Bibcode:1944PA.....52....8D. 
  10. ^ Allen, R. H. (1963), Star Names: Their Lore and Meaning (Reprint ed.), New York: Dover Publications Inc, p. 53, ISBN 0-486-21079-0, retrieved 2010-12-12. 
  11. ^ (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.
  12. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 14 日

External links[edit]