Nu2 Columbae

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ν2 Columbae
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Columba
Right ascension 05h 37m 44.61799s[1]
Declination −28° 41′ 22.8863″[1]
Apparent magnitude (V) 5.31[2]
Spectral type F5 V[3]
U−B color index +0.10[2]
B−V color index +0.46[2]
Radial velocity (Rv) +38.0±2.6[4] km/s
Proper motion (μ) RA: −37.66[1] mas/yr
Dec.: +42.42[1] mas/yr
Parallax (π) 24.51 ± 0.29[1] mas
Distance 133 ± 2 ly
(40.8 ± 0.5 pc)
Absolute magnitude (MV) +2.21[5]
Mass 1.65[4] M
Radius 1.6[6] R
Luminosity 10[7] L
Surface gravity (log g) 3.91[8] cgs
Temperature 6,473±80[4] K
Metallicity [Fe/H] −0.11±0.15[9] dex
Rotational velocity (v sin i) 27.2[8] km/s
Age 1.8[4] Gyr
Other designations
ν2 Col, CD−28° 2321, HD 37495, HIP 26460, HR 1935, SAO 170613.[10]
Database references

Nu2 Columbae is a solitary[11] star in the southern constellation of Columba. It can be seen with the naked eye, having an apparent visual magnitude of 5.31.[2] With an annual parallax shift of 24.51 mas,[1] it is estimated to lie about 133 light years from the Sun.

This star has a stellar classification of F5 V,[3] indicating that it is an F-type main sequence star that is generating energy through the thermonuclear fusion of hydrogen into helium in its core region. It has about 1.65[4] times the mass of the Sun and 1.6[6] times the Sun's radius. X-ray emission has been detected from this star, with an estimated luminosity of 1.6 × 1029 erg s−1.[5] It is about 1.8[4] billion years old and is spinning with a projected rotational velocity of 27.2 km/s.[8] The star is radiating about 10[7] times the solar luminosity from its outer atmosphere at an effective temperature of 6,473 K.[4]


  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 Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99), Bibcode:1966CoLPL...4...99J. 
  3. ^ a b Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, 3, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1982MSS...C03....0H. 
  4. ^ a b c d e f g Casagrande, L.; et al. (2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy & Astrophysics, 530 (A138): 21, Bibcode:2011A&A...530A.138C, arXiv:1103.4651Freely accessible, doi:10.1051/0004-6361/201016276. 
  5. ^ a b Pizzolato, N.; et al. (September 2000), "Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases", Astronomy and Astrophysics, 361: 614–628, Bibcode:2000A&A...361..614P. 
  6. ^ 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. 
  7. ^ a b 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. 
  8. ^ a b c Schröder, C.; et al. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo", Astronomy and Astrophysics, 493 (3): 1099–1107, Bibcode:2009A&A...493.1099S, doi:10.1051/0004-6361:200810377. 
  9. ^ Balachandran, Suchitra (May 1, 1990), "Lithium depletion and rotation in main-sequence stars", Astrophysical Journal, Part 1, 354: 310–332, Bibcode:1990ApJ...354..310B, doi:10.1086/168691. 
  10. ^ "nu.02 Col -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-12-30. 
  11. ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, Bibcode:2008MNRAS.389..869E, arXiv:0806.2878Freely accessible, doi:10.1111/j.1365-2966.2008.13596.x.