Gamma Sagittae

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γ Sagittae
Sagitta constellation map.svg
Red circle.svg

Location of γ Sagittae (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Sagitta
Right ascension 19h 58m 45.42863s[1]
Declination +19° 29′ 31.7281″[1]
Apparent magnitude (V) +3.47[2]
Evolutionary stage Red Giant
Spectral type M0- III[3]
U−B color index +1.93[2]
B−V color index +1.57[2]
Radial velocity (Rv) −34.00 ± 0.2[4] km/s
Proper motion (μ) RA: 66.21 ± 0.14[1] mas/yr
Dec.: 22.22 ± 0.12[1] mas/yr
Parallax (π) 12.62 ± 0.18[1] mas
Distance 258 ± 4 ly
(79 ± 1 pc)
Absolute magnitude (MV) −1.11[5]
Mass 1.37[6] M
Radius 55[7] R
Luminosity 562±75[7] L
Surface gravity (log g) 1.71[8] cgs
Temperature 3805[7] K
Metallicity [Fe/H] -0.14[7] dex
Other designations
γ Sagittae, γ Sge, Gamma Sge, 12 Sagittae, BD+19 4229, FK5 752, GC 27672, HD 189319, HIP 98337, HR 7635, PPM 137344, SAO 105500
Database references

Gamma Sagittae (Gamma Sge, γ Sagittae, γ Sge) is the brightest star in constellation Sagitta and is a red giant with an apparent magnitude of +3.47. It is approximately 258 ± 4 light years from Earth


The spectral type of γ Sagittae has been variously classified between K5 III and M0 III.[9]


In Chinese, 左旗 (Zuǒ Qí), meaning Left Flag, refers to an asterism consisting of γ Sagittae, α Sagittae, β Sagittae, δ Sagittae, ζ Sagittae, 13 Sagittae, 11 Sagittae, 14 Sagittae and ρ Aquilae. Consequently, γ Sagittae itself is known as 左旗五 (Zuǒ Qí wǔ, English: the Fifth Star of Left Flag.)[10]


  1. ^ a b c d e van Leeuwen, F. (2007). "Validation of the New Hipparcos Reduction". Astronomy and Astrophysics. 474 (2): 653–64. Bibcode:2007A&A...474..653V. arXiv:0708.1752Freely accessible. doi:10.1051/0004-6361:20078357. 
  2. ^ a b c Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D. 
  3. ^ Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series (ISSN 0067-0049). 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373. 
  4. ^ Famaey, B.; Jorissen, A.; Luri, X.; Mayor, M.; Udry, S.; Dejonghe, H.; Turon, C. (2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics. 430: 165. Bibcode:2005A&A...430..165F. arXiv:astro-ph/0409579Freely accessible. doi:10.1051/0004-6361:20041272. 
  5. ^ Setiawan, J.; et al. (July 2004), "Precise radial velocity measurements of G and K giants. Multiple systems and variability trend along the Red Giant Branch", Astronomy and Astrophysics, 421: 241−254, Bibcode:2004A&A...421..241S, doi:10.1051/0004-6361:20041042-1. 
  6. ^ Reffert, Sabine; Bergmann, Christoph; Quirrenbach, Andreas; Trifonov, Trifon; Künstler, Andreas (2015). "Precise radial velocities of giant stars. VII. Occurrence rate of giant extrasolar planets as a function of mass and metallicity". Astronomy & Astrophysics. 574: A116. Bibcode:2015A&A...574A.116R. arXiv:1412.4634Freely accessible. doi:10.1051/0004-6361/201322360. 
  7. ^ a b c d Piau, L.; Kervella, P.; Dib, S.; Hauschildt, P. (2011). "Surface convection and red-giant radius measurements". Astronomy and Astrophysics. 526: 12. Bibcode:2011A&A...526A.100P. arXiv:1010.3649Freely accessible. doi:10.1051/0004-6361/201014442. A100. 
  8. ^ Bluhm, P.; Jones, M. I.; Vanzi, L.; Soto, M. G.; Vos, J.; Wittenmyer, R. A.; Drass, H.; Jenkins, J. S.; Olivares, F.; Mennickent, R. E.; Vučković, M.; Rojo, P.; Melo, C. H. F. (2016). "New spectroscopic binary companions of giant stars and updated metallicity distribution for binary systems". Astronomy & Astrophysics. 593: A133. Bibcode:2016A&A...593A.133B. arXiv:1608.08260Freely accessible. doi:10.1051/0004-6361/201628459. 
  9. ^ Skiff, B. A. (2014). "VizieR Online Data Catalog: Catalogue of Stellar Spectral Classifications (Skiff, 2009-2016)". VizieR On-line Data Catalog: B/mk. Originally published in: Lowell Observatory (October 2014). 1. Bibcode:2014yCat....1.2023S. 
  10. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 3 日