Rho3 Eridani

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ρ3 Eridani
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Eridanus
Right ascension 03h 04m 16.51707s[1]
Declination −07° 36′ 03.0859″[1]
Apparent magnitude (V) 5.26[2]
Spectral type A5 V[3]
U−B color index +0.07[2]
B−V color index +0.21[2]
Radial velocity (Rv)15.0±4.2[4] km/s
Proper motion (μ) RA: +67.56[1] mas/yr
Dec.: +17.43[1] mas/yr
Parallax (π)24.06 ± 0.40[1] mas
Distance136 ± 2 ly
(41.6 ± 0.7 pc)
Absolute magnitude (MV)+2.17[5]
Mass1.83[6] M
Radius1.2[7] R
Luminosity10[8] L
Temperature7,400[8] K
Rotational velocity (v sin i)186[9] km/s
Age500[6] Myr
Other designations
ρ3 Eridani, ρ3 Eri, 10 Eridani, BD-08° 572, HD 19107, HIP 14293, HR 925, SAO 130269.[10]
Database references

Rho3 Eridani, Latinized from ρ3 Eridani, is a star located in the constellation Eridanus. It forms an asterism with Rho1 and Rho2 Eridani, south of Cetus, in the upper north east portion of Eridanus. The star has an apparent visual magnitude of 5.26,[2] which is bright enough to be seen with the naked eye on a dark, clear night. The distance to this star, as determined via the parallax method,[1] is about 136 light years.

This is an A-type main sequence star with a stellar classification of A5 V.[3] (Some sources list it as A8 V.)[11] It is some 500 million years old and is spinning rapidly with a projected rotational velocity of 186 km/s.[9] This rotation is giving the star a slightly oblate shape, with the equator being 5% larger than the poles.[11] The star has about 120% of the radius of the Sun,[7] and 183% of the Sun's mass. It shines with 10 times the solar luminosity from its outer atmosphere at an effective temperature of 7,400 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, arXiv:0708.1752Freely accessible, Bibcode:2007A&A...474..653V, 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 ^ a b c d Mermilliod, J.-C. (1986), Compilation of Eggen's UBV data, transformed to UBV (unpublished), SIMBAD, Bibcode:1986EgUBV........0M. 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 Abt, Helmut A.; Morrell, Nidia I. (July 1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement, 99: 135, Bibcode:1995ApJS...99..135A, doi:10.1086/192182. 
  4. ^ 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:1606.08053Freely accessible, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065. 
  5. ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971Freely accessible, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015. 
  6. ^ a b 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, arXiv:1311.7141Freely accessible, Bibcode:2014MNRAS.437.1216D, 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: 521–524, arXiv:astro-ph/0012289Freely accessible, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451. 
  8. ^ a b c McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037Freely accessible, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x. 
  9. ^ a b Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785Freely accessible, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224. 
  10. ^ "* rho03 Eri". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-10-12. 
  11. ^ a b van Belle, Gerard T., Gerard T. (March 2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review, 20 (1): 51, arXiv:1204.2572Freely accessible, Bibcode:2012A&ARv..20...51V, doi:10.1007/s00159-012-0051-2.