Beta Sagittae

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Beta Sagittae
Diagram showing star positions and boundaries of the Sagitta constellation and its surroundings
Cercle rouge 100%.svg

Location of β Sagittae (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Sagitta
Right ascension 19h 41m 02.9393s[1]
Declination +17° 28′ 33.748″[1]
Apparent magnitude (V) 4.387[1]
Characteristics
Spectral type G8IIIa[1]
U−B color index +0.89[2]
B−V color index +1.05[2]
R−I color index +0.50[2]
Astrometry
Radial velocity (Rv) −22.4 ± 0.9[1] km/s
Proper motion (μ) RA: 9.06[1] mas/yr
Dec.: −33.90[1] mas/yr
Parallax (π) 6.99 ± 0.67[1] mas
Distance 470 ± 40 ly
(140 ± 10 pc)
Absolute magnitude (MV) –1.39+0.22
−0.20
[3]
Details
Radius 10[4] R
Surface gravity (log g) 2.79[3] cgs
Temperature 4,850[3] K
Metallicity [Fe/H] –0.03[3] dex
Rotational velocity (v sin i) 9.1 ± 0.[3] km/s
Other designations
β Sagittae, β Sge, Beta Sge, 6 Sagittae, BD+17 4048, FK5 1513, GC 27236, HD 185958, HIP 96837, HR 7488, PPM 136766, SAO 105133.[1]
Database references
SIMBAD data

Beta Sagittae (Beta Sge, β Sagittae, β Sge) is a G-type giant star in the constellation of Sagitta.[1] It has an apparent visual magnitude of approximately 4.387.[1]

Beta Sagittae projected Galactic orbit carries it between 18,400 and 24,100 light years from the center of the Galaxy. [5]

Beta Sagittae will come closest to the Sun 3.0 million years from now when it will brighten to magnitude 3.64 from a distance of 310 light years. [5]

Naming[edit]

In Chinese, 左旗 (Zuǒ Qí), meaning Left Flag, refers to an asterism consisting of β Sagittae, α Sagittae, δ Sagittae, ζ Sagittae, γ Sagittae, 13 Sagittae, 11 Sagittae, 14 Sagittae and ρ Aquilae. Consequently, β Sagittae itself is known as 左旗二 (Zuǒ Qí èr, English: the Second Star of Left Flag.)[6]

References[edit]

  1. ^ a b c d e f g h i j k * bet Sge -- Star, database entry, SIMBAD. Accessed on line October 13, 2010.
  2. ^ a b c HR 7488, 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 October 13, 2010.
  3. ^ a b c d e Carney, Bruce W. et al. (March 2008), "Rotation and Macroturbulence in Metal-Poor Field Red Giant and Red Horizontal Branch Stars", The Astronomical Journal 135 (3): 892–906, arXiv:0711.4984, Bibcode:2008AJ....135..892C, doi:10.1088/0004-6256/135/3/892 
  4. ^ HD 185958, database entry, Catalog of Apparent Diameters and Absolute Radii of Stars (CADARS), 3rd edition, L. E. Pasinetti-Fracassini, L. Pastori, S. Covino, and A. Pozzi, CDS ID II/224. Accessed on line October 13, 2010.
  5. ^ a b Beta Sagittae (HIP 96837)
  6. ^ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 3 日