HD 6

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) 6.30±0.01[2]
Characteristics
Evolutionary stage horizontal branch[3]
Spectral type K0 III[4]
U−B color index +1.03[5]
B−V color index +1.11[5]
Astrometry
Radial velocity (Rv)15.3±0.7[6] km/s
Proper motion (μ) RA: +45.245 mas/yr[1]
Dec.: −53.594 mas/yr[1]
Parallax (π)6.9277 ± 0.0368 mas[1]
Distance471 ± 3 ly
(144.3 ± 0.8 pc)
Absolute magnitude (MV)0.62[7]
Details
Mass1.95[8] M☉
Radius12.4[9] R☉
Luminosity72.4[10] L☉
Surface gravity (log g)1.8[3] cgs
Temperature4,807±75[9] K
Metallicity [Fe/H]−0.03[3] dex
Rotational velocity (v sin i)2.8±0.8[11] km/s
Age1.62[8] Gyr
Other designations
62 G. Piscium, AG−00°4, BD−01°4525, GC 51, HD 6, HIP 417, HR 2, SAO 128569[12]
Database references
SIMBADdata

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 6.3.[2] The star is located at a distance of 471 light years from the Sun based on parallax,[1] and is drifting further away with a radial velocity of 15.3 km/s.[6] It has an absolute magnitude of 0.62.[7]

An evolved red giant with a stellar classification K0 III,[4] the star has moved off the main sequence by cooling and expanding. At the age of 1.6 billion years,[8] is now a red clump giant on the horizontal branch that is engaged in core helium fusion.[3] It has nearly double the mass of the Sun[8] and has expanded to 12.4[9] times the Sun's radius. The star is radiating 72 times the luminosity of the Sun[10] from its photosphere at an effective temperature of 4,807 K.[9]

References

  1. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  2. ^ a b Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
  3. ^ a b c d 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. ^ a b 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. ^ a b Cousins, A. W. J. (1971). "Photometric standard stars". Royal Observatory Annals. 7. Bibcode:1971ROAn....7.....C.
  6. ^ a b Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. eISSN 1562-6873. ISSN 1063-7737. S2CID 119231169.
  7. ^ a b 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.
  8. ^ a b c d Demarque, Pierre; Woo, Jong-Hak; Kim, Yong-Cheol; Yi, Sukyoung K. (December 2004). "Y 2 Isochrones with an Improved Core Overshoot Treatment". The Astrophysical Journal Supplement Series. 155 (2): 667–674. arXiv:astro-ph/0409024. Bibcode:2004ApJS..155..667D. doi:10.1086/424966. eISSN 1538-4365. ISSN 0067-0049.
  9. ^ a b c d Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. eISSN 1538-3881.
  10. ^ a b Luck, R. Earle (25 August 2015). "Abundances in the Local Region. I. G and K Giants". The Astronomical Journal. 150 (3): 88. arXiv:1507.01466. Bibcode:2015AJ....150...88L. doi:10.1088/0004-6256/150/3/88. eISSN 1538-3881. ISSN 0004-6256. S2CID 118505114.
  11. ^ Fekel, Francis C.; Watson, Lyndon C. (November 1998). "A Search for Lithium-rich Giants among Stars with Infrared Excesses". The Astronomical Journal. 116 (5): 2466–2474. Bibcode:1998AJ....116.2466F. doi:10.1086/300614. ISSN 0004-6256.
  12. ^ "HD 6". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-07-02.