Nu2 Columbae

Nu² Columbae is a solitary star^[11] 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.

For other stars with this Bayer designation, see ν Columbae.

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]
Characteristics
Spectral type	F5 V[3]
U−B color index	+0.10[2]
B−V color index	+0.46[2]
Astrometry
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 mas[1]
Distance	133 ± 2 ly (40.8 ± 0.5 pc)
Absolute magnitude (MV)	+2.21[5]
Details
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
SIMBAD	data

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 times the mass of the Sun^[4] and 1.6 times the Sun's radius.^[6] X-ray emission has been detected from this star, with an estimated luminosity of 1.6×10²⁹ erg/s.^[5] It is about 1.8 billion years old^[4] and is spinning with a projected rotational velocity of 27.2 km/s.^[8] The star is radiating about 10 times the solar luminosity from its outer atmosphere^[7] at an effective temperature of 6,473 K.^[4]

References

1. van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
2. Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
3. Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 3, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
4. 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, arXiv:1103.4651, Bibcode:2011A&A...530A.138C, doi:10.1051/0004-6361/201016276, S2CID 56118016.
5. 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. 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, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
7. 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:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
8. Schröder, C.; Reiners, Ansgar; Schmitt, Jürgen H. M. M. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo" (PDF), Astronomy and Astrophysics, 493 (3): 1099–1107, Bibcode:2009A&A...493.1099S, doi:10.1051/0004-6361:200810377^{[permanent dead link‍]}
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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.