Xi Eridani

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ξ Eridani
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Eridanus
Right ascension 04h 23m 40.85270s[1]
Declination −03° 44′ 43.6771″[1]
Apparent magnitude (V) 5.17[2]
Spectral type A2 V[3]
U−B color index +0.08[2]
B−V color index +0.08[2]
Radial velocity (Rv) −11.0[4] km/s
Proper motion (μ) RA: −47.36[1] mas/yr
Dec.: −54.91[1] mas/yr
Parallax (π) 15.60 ± 0.25[1] mas
Distance 209 ± 3 ly
(64 ± 1 pc)
Absolute magnitude (MV) +1.59[5]
Mass 2.29[6] M
Radius 2.2[7] R
Luminosity 27.6[8] L
Surface gravity (log g) 3.73[9] cgs
Temperature 8,400[8] K
Rotational velocity (v sin i) 194.3±2.3[3] km/s
Age 450[6] Myr
Other designations
ξ Eri, BD−04° 818, 42 Eridani, FK5 1120, HD 27861, HIP 20507, HR 1383, SAO 131176.[10]
Database references

ξ Eridani (Latinised as Xi Eridani) is a solitary[6] star in the constellation Eridanus. With an apparent visual magnitudeof 5.17,[2] it is faintly visible to the naked eye on a clear, dark night. Based upon an annual parallax shift of 0.00156 arcseconds,[1] it is located around 209 light years from the Sun. The star is considered a member of the Sirius supercluster.[5]

This is an ordinary A-type main sequence star with a stellar classification of A2 V,[3] indicating that it is generating energy through the thermonuclear fusion of hydrogen into helium in its core region. It is around 450[6] million years old and has a relatively high rate of rotation with a projected rotational velocity of 194 km/s.[3] The star has about 2.3 times the mass of the Sun,[6] 2.2 times the Sun's radius,[7] and radiates 27.6[8] times the solar luminosity from its outer atmosphere at an effective temperature of 8,400 K.[8]


  1. ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752Freely accessible, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", SIMBAD, Bibcode:1986EgUBV........0M. 
  3. ^ a b c d Díaz, C. G.; et al. (July 2011), "Accurate stellar rotational velocities using the Fourier transform of the cross correlation maximum", Astronomy & Astrophysics, 531: A143, Bibcode:2011A&A...531A.143D, arXiv:1012.4858Freely accessible, doi:10.1051/0004-6361/201016386. 
  4. ^ Wielen, R.; et al. (1999), Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions, 35, Veröffentlichungen des Astronomisches Rechen-Institut Heidelberg, Bibcode:1999VeARI..35....1W. 
  5. ^ a b Eggen, Olin J. (August 1998), "The Sirius Supercluster and Missing Mass near the Sun", The Astronomical Journal, 116 (2): 782–788, Bibcode:1998AJ....116..782E, doi:10.1086/300465. 
  6. ^ a b c d e De Rosa, R. J.; et al. (January 2014), "The VAST Survey – III. The multiplicity of A-type stars within 75 pc", Monthly Notices of the Royal Astronomical Society, 437 (2): 1216–1240, Bibcode:2014MNRAS.437.1216D, arXiv:1311.7141Freely accessible, doi:10.1093/mnras/stt1932. 
  7. ^ a b Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) – Third edition – Comments and statistics", Astronomy and Astrophysics, 367 (2): 521–524, Bibcode:2001A&A...367..521P, arXiv:astro-ph/0012289Freely accessible, doi:10.1051/0004-6361:20000451. 
  8. ^ a b c d McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, Bibcode:2012MNRAS.427..343M, arXiv:1208.2037Freely accessible, doi:10.1111/j.1365-2966.2012.21873.x. 
  9. ^ King, Jeremy R.; et al. (April 2003), "Stellar Kinematic Groups. II. A Reexamination of the Membership, Activity, and Age of the Ursa Major Group", The Astronomical Journal, 125 (4): 1980–2017, Bibcode:2003AJ....125.1980K, doi:10.1086/368241. 
  10. ^ "* ksi Eri". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-11-03.