Gliese 809

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Gliese 809
Observation data
Epoch J2000      Equinox J2000
Constellation Cepheus
Right ascension 20h 53m 19.79051s[1]
Declination +62° 09′ 15.8028″[1]
Apparent magnitude (V) 8.54[2]
Spectral type M2V[2]
Radial velocity (Rv) −17.30±0.09[3] km/s
Proper motion (μ) RA: 1.56[1] mas/yr
Dec.: −774.55[1] mas/yr
Parallax (π) 141.87 ± 0.64[1] mas
Distance 23.0 ± 0.1 ly
(7.05 ± 0.03 pc)
Absolute magnitude (MV) 9.31[4]
Mass 0.614[2] M
Radius 0.705±0.023[5] R
Temperature 3,597[2] K
Metallicity [Fe/H] −0.06[2] dex
Rotational velocity (v sin i) 2.8[2] km/s
Other designations
GJ 809 A, HD 199305, HIP 103096, TYC 4251-655-1[6]
Database references

Gliese 809 is a red dwarf star in the constellation Cepheus,[4] forming the primary component of a multi-star system. A visual magnitude of 8.55 makes it too faint to see with the naked eye. It is part of the Gliese Catalogue of Nearby Stars and is located about 23 light-years (ly) from the Solar System. Gliese 809 has about 70.5%[5] the radius of the Sun and 61.4%[2] of the Sun's mass. It has a metallicity of −0.06, which means that the abundance of elements other than hydrogen and helium is just 87.1% that of the Sun.[2]

This is a high proper motion star that moves about 0.77 arcseconds per year relative to background stars.[6] In physical terms it is travelling with a space velocity of 31.1 km/s relative to the Solar System.[4] The galactic orbit of this star carries it 21,300 ly from the Galactic Center at its perigee to 30,600 ly at its apogee. The orbital eccentricity is 17.8% with the semi-major axis of 25,956 ly and a semi-minor axis of 25,542 ly.[4]

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 e f g h Jenkins, J. S.; Ramsey, L. W.; Jones, H. R. A.; Pavlenko, Y.; Gallardo, J.; Barnes, J. R.; Pinfield, D. J. (October 2009), "Rotational Velocities for M Dwarfs", The Astrophysical Journal, 704 (2): 975–988, arXiv:0908.4092Freely accessible, Bibcode:2009ApJ...704..975J, doi:10.1088/0004-637X/704/2/975. 
  3. ^ Nidever, David L.; et al. (August 2002), "Radial Velocities for 889 Late-Type Stars", The Astrophysical Journal Supplement Series, 141 (2): 503–522, arXiv:astro-ph/0112477Freely accessible, Bibcode:2002ApJS..141..503N, doi:10.1086/340570. 
  4. ^ a b c d "Gliese 809 (HIP 103096)". Ashland Astronomy Studio. Retrieved 28 March 2014. 
  5. ^ a b Houdebine, E. R. (September 2010), "Observation and modelling of main-sequence star chromospheres - XIV. Rotation of dM1 stars", Monthly Notices of the Royal Astronomical Society, 407 (3): 1657–1673, Bibcode:2010MNRAS.407.1657H, doi:10.1111/j.1365-2966.2010.16827.x. 
  6. ^ a b "Gliese 809". SIMBAD Astronomical Database. Retrieved 2015-07-06.