Gamma2 Sagittarii

Source: Wikipedia, the free encyclopedia.
For other stars with this Bayer designation, see γ Sagittarii.
γ2 Sagittarii
Location of γ2 Sagittarii (circled)
Observation data
J2000.0
Constellation Sagittarius
Right ascension 18h 05m 48.48810s[1]
Declination –30° 25′ 26.7235″[1]
Apparent magnitude (V) +2.98[2]
Characteristics
Spectral type K1 III[2]
U−B color index +0.77[3]
B−V color index +1.01[3]
Distance
96.9 ± 0.5 ly
(29.7 ± 0.2 pc)
Absolute magnitude (MV)+0.62[4]
Details
dex
FK5 679, GC 24632, HD 165135, HIP 88635, HR 6746, PPM 297231, SAO 209696[8]
Database references
SIMBADdata

Gamma2 Sagittarii (γ2 Sagittarii, abbreviated Gamma2 Sgr, γ2 Sgr), formally named Alnasl

apparent visual magnitude of +2.98,[2] making it the seventh-brightest star
in the constellation.

It forms part of a

variable star designation W Sagittarii.[10][11]

Nomenclature

γ2 Sagittarii (Latinised to Gamma2 Sagittarii) is the star's Bayer designation.

It bore the traditional names Alnasl (alternatively Nasl, El Nasl, "al Nasl"), Nushaba (Nash) and Awal al Warida. Alnasl is derived from the Arabic النصل al-naşl and Nushaba is derived from the Arabic Zujj al-Nashshaba, both meaning "arrowhead".[12][13] In the catalogue of stars in the calendarium of al Achsasi al Mouakket, this star was designated Awal al Waridah, meaning "first [star] of the [ostrich] going down to the water", from the Arabic النعامة الواردة al Naʽāma al Wārida, the name of the asterism consisting of this star, Delta Sagittarii, Epsilon Sagittarii and Eta Sagittarii. This ostrich was thought of as going down to the river (the Milky Way) to drink, and another ostrich (σ, φ, τ, and ζ, al Sadira) was thought of as coming back up.[14][13]

In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[15] to catalogue and standardize proper names for stars. The WGSN approved the name Alnasl for this star on 21 August 2016 and it is now so included in the List of IAU-approved Star Names.[9]

Gamma2 Sagittarii, together with Delta Sagittarii, Epsilon Sagittarii, Zeta Sagittarii, Lambda Sagittarii, Sigma Sagittarii, Tau Sagittarii and Phi Sagittarii, comprise the Teapot asterism.[16]

Together with Delta Sagittarii and Epsilon Sagittarii, Gamma2 Sagittarii formed the Akkadian Sin-nun‑tu, or Si-nu-nu‑tum 'the Swallow'.[13]

In

Winnowing Basket, refers to an asterism consisting of Gamma Sagittarii, Delta Sagittarii, Epsilon Sagittarii and Eta Sagittarii. Consequently, Gamma2 Sagittarii itself is known as 箕宿一 (Jī Sù yī, English: the First Star of Winnowing Basket.)[17]

Properties

A

K-type stars
.

References

  1. ^
    S2CID 18759600
  2. ^
    Bibcode:1999VeARI..35....1W
  3. ^
    Bibcode:1966CoLPL...4...99J
  4. ^
    S2CID 119257644
    .
  5. ^
    S2CID 425754
  6. ^
    doi:10.1086/191527
  7. Bibcode:1907fbs..book.....O
  8. Centre de Données astronomiques de Strasbourg
    , retrieved 2012-01-05
  9. ^ a b "Naming Stars". IAU.org. Retrieved 16 December 2017.
  10. University of Illinois
    , retrieved 2012-01-05
  11. ISBN 0-486-23673-0
  12. ISBN 0-7188-2695-7
  13. ^
    ISBN 0-486-21079-0
    . Retrieved 2012-09-04.
  14. doi:10.1093/mnras/55.8.429
    .
  15. ^ IAU Working Group on Star Names (WGSN), International Astronomical Union, retrieved 22 May 2016.
  16. ^ "Teapot". constellation-guide.com. Retrieved 2017-05-13.
  17. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 11 日
  18. Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original
    on 2012-03-18, retrieved 2012-01-16
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