Gamma Pyxidis

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Gamma Pyxidis
Diagram showing star positions and boundaries of the Pyxis constellation and its surroundings
Cercle rouge 100%.svg

Location of γ Pyxidis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Pyxis
Right ascension 08h 50m 31.9233s[1]
Declination −27° 42′ 35.440″[1]
Apparent magnitude (V) 4.026[2]
Spectral type K3III[2]
U−B color index +1.368[3]
B−V color index +1.284[3]
Radial velocity (Rv) 24.5 km/s
Proper motion (μ) RA: −134.31[4] mas/yr
Dec.: 87.89[4] mas/yr
Parallax (π) 15.73 ± 0.17[4] mas
Distance 207 ± 2 ly
(63.6 ± 0.7 pc)
Luminosity 178[5] L
Surface gravity (log g) 2.35[6] cgs
Temperature 4,270[6] K
Metallicity [Fe/H] -0.05[6] dex
Other designations
γ Pyxidis, γ Pyx, Gamma Pyx, CPD−27  3442, FK5 332, GC 12216, HD 75691, HR 3518, HIP 43409, SAO 176559.
Database references

Gamma Pyxidis (Gamma Pyx, γ Pyxidis, γ Pyx) is a 4th magnitude star in the constellation Pyxis. It is classified as a giant star of composition similar to the Sun[7] with an estimated diameter 3.7 times that of the Sun.[8] It is located an estimated 207 light years from the Solar System.[4]

Gamma Pyxidis is moving through the Galaxy at a speed of 54.2 km/s relative to the Sun. Its projected Galactic orbit carries it between 21,300 and 30,700 light years from the center of the Galaxy.[9]


In Chinese, 天狗 (Tiān Gǒu), meaning Celestial Dog, refers to an asterism consisting of γ Pyxidis, e Velorum, f Velorum, β Pyxidis, α Pyxidis and δ Pyxidis. Consequently, γ Pyxidis itself is known as 天狗六 (Tiān Gǒu liù, English: the Sixth Star of Celestial Dog.)[10]


  1. ^ a b Perryman, M. A. C.; et al. (1997), "The Hipparcos Catalogue", Astronomy & Astrophysics, 323: L49–L52, Bibcode:1997A&A...323L..49P 
  2. ^ a b "gam Pyx", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2009-06-03 
  3. ^ a b Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement, 15: 459, Bibcode:1968ApJS...15..459G, doi:10.1086/190168 
  4. ^ a b c d van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752Freely accessible. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. 
  5. ^ Mallik, Sushma V. (December 1999), "Lithium abundance and mass", Astronomy and Astrophysics, 352: 495–507, Bibcode:1999A&A...352..495M 
  6. ^ a b c Cenarro, A. J.; et al. (2007), "Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters", Monthly Notices of the Royal Astronomical Society, 374 (2): 664–690, arXiv:astro-ph/0611618Freely accessible, Bibcode:2007MNRAS.374..664C, doi:10.1111/j.1365-2966.2006.11196.x 
  7. ^ Keenan, Philip C.; Barnbaum, Cecilia (June 1999), "Revision and Calibration of MK Luminosity Classes for Cool Giants by HIPPARCOS Parallaxes", The Astrophysical Journal, 518 (2): 859–865, Bibcode:1999ApJ...518..859K, doi:10.1086/307311 
  8. ^ Pasinetti Fracassini, L. E.; Pastori, L.; Covino, S.; Pozzi, A. (2001). "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) – Third edition – Comments and statistics". Astronomy & Astrophysics. 367 (2): 521–24. arXiv:astro-ph/0012289Freely accessible. Bibcode:2001A&A...367..521P. doi:10.1051/0004-6361:20000451. 
  9. ^ Gamma Pyxidis (HIP 43409)
  10. ^ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 17 日