HD 6

HD 6 is a star in the equatorial constellation of Pisces, and is located a couple of degrees southeast of the intersection between the ecliptic and the celestial equator. It is a yellow-hued star that is just barely visible to the naked eye with an apparent visual magnitude of 6.32.[2] The star is located at a distance of approximately 218 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +15 km/s.[1] It has an absolute magnitude of 0.62.[2]

HD 6
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Pisces
Right ascension 00h 05m 03.82339s[1]
Declination −00° 30 10.9306[1]
Apparent magnitude (V) 6.32[2]
Characteristics
Evolutionary stage horizontal branch[3]
Spectral type G9III[4]
B−V color index 1.099±0.001[2]
Astrometry
Radial velocity (Rv)+14.98±0.14[1] km/s
Proper motion (μ) RA: +44.622[1] mas/yr
Dec.: −53.462[1] mas/yr
Parallax (π)14.98 ± 0.14[1] mas
Distance218 ± 2 ly
(66.8 ± 0.6 pc)
Absolute magnitude (MV)0.62[2]
Details
Mass1.4[3] M
Radius12.75+0.59
−0.42
[1] R
Luminosity74.0±1.3[1] L
Surface gravity (log g)1.8[3] cgs
Temperature4,740+80
−105
[1] K
Metallicity [Fe/H]−0.03[3] dex
Age9.00±0.12[5] Gyr
Other designations
BD−01°4525, HD 6, HIP 417, HR 2, SAO 128569[6]
Database references
SIMBADdata

An evolved red giant with a stellar classification G9III,[4] the star has moved off the main sequence by cooling and expanding. At the age of nine billion years,[5] is now a red clump giant on the horizontal branch that is engaged in core helium fusion.[3] It has an estimated 1.4[3] times the mass of the Sun and has expanded to 13[1] times the Sun's radius. The star is radiating 74 times the luminosity of the Sun from its photosphere at an effective temperature of 4,740 K.[1]

References

  1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  3. Tautvaišienė, G.; et al. (March 2013), "Red clump stars of the Milky Way - laboratories of extra-mixing", Monthly Notices of the Royal Astronomical Society, 430 (1): 621–627, arXiv:1304.4393, Bibcode:2013MNRAS.430..621T, doi:10.1093/mnras/sts663, S2CID 119211439.
  4. Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
  5. Feuillet, Diane K.; et al. (2016), "Determining Ages of APOGEE Giants with Known Distances", The Astrophysical Journal, 817 (1): 40, arXiv:1511.04088, Bibcode:2016ApJ...817...40F, doi:10.3847/0004-637X/817/1/40, S2CID 118675933.
  6. "HD 6". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-07-02.

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