Astronomy:HD 6

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Short description: Star in the constellation Pisces
HD 6
Location of HD 6 (circled in red)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Pisces[1]
Right ascension  00h 05m 03.82275s[2]
Declination −00° 30′ 10.9286″[2]
Apparent magnitude (V) 6.30±0.01[3]
Characteristics
Evolutionary stage horizontal branch[4]
Spectral type K0 III[5]
U−B color index +1.03[6]
B−V color index +1.11[6]
Astrometry
Radial velocity (Rv)+14.91±0.12[2] km/s
Proper motion (μ) RA: +45.245[2] mas/yr
Dec.: −53.594[2] mas/yr
Parallax (π)6.9277 ± 0.0368[2] mas
Distance471 ± 3 ly
(144.3 ± 0.8 pc)
Absolute magnitude (MV)0.62[1]
Details
Mass1.95[7] M☉
Radius12.4[8] R☉
Luminosity72.4[9] L☉
Surface gravity (log g)1.8[4] cgs
Temperature4,807±75[8] K
Metallicity [Fe/H]−0.03[4] dex
Rotational velocity (v sin i)2.8±0.8[10] km/s
Age1.62[7] Gyr
Other designations
BD−01°4525, GC 51, HD 6, HIP 417, HR 2, SAO 128569[11][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.[3] The star is located at a distance of 471 light-years from the Sun based on parallax, and is drifting further away with a radial velocity of 14.9 km/s.[2] It has an absolute magnitude of 0.62.[1]

An evolved red giant with a stellar classification K0 III,[5] the star has moved off the main sequence by cooling and expanding. At the age of 1.6 billion years,[7] is now a red clump giant on the horizontal branch that is engaged in core helium fusion.[4] It has nearly double the mass of the Sun[7] and has expanded to 12.4[8] times the Sun's radius. The star is radiating 72 times the luminosity of the Sun[9] from its photosphere at an effective temperature of 4,807 K.[8]

References

  1. ↑ 1.0 1.1 1.2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A. 
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  3. ↑ 3.0 3.1 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. ISSN 0004-6361. Bibcode: 2000A&A...355L..27H. 
  4. ↑ 4.0 4.1 4.2 4.3 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, doi:10.1093/mnras/sts663, Bibcode: 2013MNRAS.430..621T. 
  5. ↑ 5.0 5.1 Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey 5, Bibcode: 1999MSS...C05....0H. 
  6. ↑ 6.0 6.1 Cousins, A. W. J. (1971). "Photometric standard stars". Royal Observatory Annals 7. Bibcode: 1971ROAn....7.....C. 
  7. ↑ 7.0 7.1 7.2 7.3 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. doi:10.1086/424966. ISSN 0067-0049. Bibcode: 2004ApJS..155..667D. 
  8. ↑ 8.0 8.1 8.2 8.3 Stassun, Keivan G. et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode: 2019AJ....158..138S. 
  9. ↑ 9.0 9.1 Luck, R. Earle (25 August 2015). "Abundances in the Local Region. I. G and K Giants". The Astronomical Journal 150 (3): 88. doi:10.1088/0004-6256/150/3/88. ISSN 0004-6256. Bibcode: 2015AJ....150...88L. 
  10. ↑ 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. doi:10.1086/300614. ISSN 0004-6256. Bibcode: 1998AJ....116.2466F. 
  11. ↑ "HD 6". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+6. 
  12. ↑ Gould, Benjamin Apthorp (1879), "Uranometria Argentina catalog of bright southern stars", Resultados del Observatorio Nacional Argentino en Cordoba (Buenos Aires) 1, Bibcode: 1879RNAO....1.....G, http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=V%2F135%2Fcatalog, retrieved 2012-05-08 

Coordinates: Sky map 00h 05m 03.80s, −00° 30′ 11.0″