Phi2 Pavonis

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Phi2 Pavonis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Dorado
Right ascension 20h 40m 02.63822s[1]
Declination −60° 32′ 56.0200″[1]
Apparent magnitude (V) +5.10[2]
Spectral type G0 V Fe-0.8 CH-0.5[3]
U−B color index −0.02[2]
B−V color index +0.53[2]
Radial velocity (Rv)−32.02±0.05[4] km/s
Proper motion (μ) RA: +313.48[1] mas/yr
Dec.: −569.91[1] mas/yr
Parallax (π)40.55 ± 0.27[1] mas
Distance80.4 ± 0.5 ly
(24.7 ± 0.2 pc)
Mass1.09±0.02 M
Radius1.86±0.05 R
Luminosity3.39 L
Surface gravity (log g)4.20±0.02 cgs
Temperature6,091±27 K
Metallicity [Fe/H]−0.38±0.04 dex
Rotation27.7±1.7 d[5]
Rotational velocity (v sin i)1.95±0.43 km/s
Age5.69±0.24 Gyr
Other designations
φ2 Pav, CD−60° 7508, GJ 9701, HD 196378, HIP 101983, HR 7875, SAO 254846[6]
Database references

Phi2 Pavonis2 Pav, φ2 Pavonis) is a solitary[7] star in the southern constellation of Pavo (the Peacock). It is faintly visible to the naked eye with an apparent visual magnitude of +5.10.[2] Based upon an annual parallax shift of 40.55 mas as seen from Earth, it is located 80.4 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.07 due to interstellar dust. It is a member of the thin disk population.[4]

This is a yellow-white hued G-type main sequence star with a stellar classification of G0 V Fe-0.8 CH-0.5.[3] This notation indicates the surface abundance of iron and cyanogen are below normal for this class of star. It is around 5.7[4] billion years old and is spinning with a period of around 28 days.[5] It has an estimated 1.09 times the mass of the Sun and is 1.86 times the Sun's radius. The star is radiating 3.39 times the solar luminosity from its photosphere at an effective temperature of 6,091 K.[4]

This system was in 1991 a test case for the Zeta Herculis moving group, of low metallicity stars with 5 billion years of age. This group includes besides Zeta Herculis: δ Trianguli, ζ Reticuli, 1 Hydrae, Gl 456, Gl 678, and Gl 9079.[8]

In 1998, using the European Southern Telescope in Chile, a planet was announced to be orbiting the star.[9] This team retracted this claim in 2002, but found a different periodicity of 7 days possibly due to stellar rotation.[10]

See also[edit]


  1. ^ a b c d e 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. 
  2. ^ a b c d Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV data, SIMBAD, Bibcode:1986EgUBV........0M. 
  3. ^ a b Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc—The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770Freely accessible, Bibcode:2006AJ....132..161G, doi:10.1086/504637. 
  4. ^ a b c d e Jofré, E.; et al. (2015), "Stellar parameters and chemical abundances of 223 evolved stars with and without planets", Astronomy & Astrophysics, 574: A50, arXiv:1410.6422Freely accessible, Bibcode:2015A&A...574A..50J, doi:10.1051/0004-6361/201424474. 
  5. ^ a b Olmedo, Manuel; et al. (December 2013), "Mg II h + k Flux—Rotational Period Correlation for G-type Stars", Publications of the Astronomical Society of the Pacific, 125 (934): 1436, arXiv:1310.3890Freely accessible, Bibcode:2013PASP..125.1436O, doi:10.1086/674332. 
  6. ^ "phi02 Pav". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-04-18. 
  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, arXiv:0806.2878Freely accessible, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x. 
  8. ^ de Mello, G. F. Porto; da Silva, L. (1991), "On the physical existence of the Zeta HER moving group – A detailed analysis of Phi exp 2 Pavonis", Astronomical Journal, 102: 1816–1825, Bibcode:1991AJ....102.1816P, doi:10.1086/116006 
  9. ^ Kürster, M. (1998), "The ESO radial velocity planet search program", Workshop: Science with Gemini,, CiteSeerX accessible. 
  10. ^ Endl, M.; et al. (2002), "The planet search program at the ESO Coudé Echelle spectrometer III. The complete Long Camera survey results", Astronomy & Astrophysics, 392 (2): 671–690, arXiv:astro-ph/0207512Freely accessible, Bibcode:2002A&A...392..671E, doi:10.1051/0004-6361:20020937.