Phi2 Pavonis

Phi2 Pavonis (φ2 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]

For other stars with this Bayer designation, see φ Pavonis.
Phi2 Pavonis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Pavo
Right ascension 20h 40m 02.63822s[1]
Declination −60° 32′ 56.0200″[1]
Apparent magnitude (V) +5.10[2]
Characteristics
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]
Astrometry
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 mas[1]
Distance80.4 ± 0.5 ly
(24.7 ± 0.2 pc)
Details[4]
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
SIMBADdata
ARICNSdata

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

References
  1. van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
  2. 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. 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/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992.
  4. Jofré, E.; et al. (2015), "Stellar parameters and chemical abundances of 223 evolved stars with and without planets", Astronomy & Astrophysics, 574: A50, arXiv:1410.6422, Bibcode:2015A&A...574A..50J, doi:10.1051/0004-6361/201424474, S2CID 53666931.
  5. 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:1310.3890, Bibcode:2013PASP..125.1436O, doi:10.1086/674332, S2CID 118395379.
  6. "phi02 Pav". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 18 April 2017.{{cite web}}: CS1 maint: postscript (link)
  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:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
  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: 58, Bibcode:1998swg..work...58K, CiteSeerX 10.1.1.53.4018.
  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/0207512, Bibcode:2002A&A...392..671E, doi:10.1051/0004-6361:20020937, S2CID 17393347.
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