Zeta Volantis

δ Volantis

Location of ζ Volantis
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Volans
Right ascension	07^h 41^m 49.26100^s[1]
Declination	−72° 36′ 21.9566″[1]
Apparent magnitude (V)	3.93[2]
Characteristics
Spectral type	K0 III[3]
B−V color index	+1.03[2]
Astrometry
Radial velocity (Rv)	48.1±0.7[4] km/s
Proper motion (μ)	RA: +33.34[1] mas/yr Dec.: +14.89[1] mas/yr
Parallax (π)	23.13 ± 0.12[1] mas
Distance	141.0 ± 0.7 ly (43.2 ± 0.2 pc)
Details
Radius	11[5] R☉
Luminosity	53[6] L☉
Surface gravity (log g)	2.43±0.10[7] cgs
Temperature	4,721±57[7] K
Metallicity [Fe/H]	−0.18±0.05[7] dex
Other designations
ζ Vol, CP−72° 627, FK5 297, HD 63295, HIP 37504, HR 3024, SAO 256438.[8]

Zeta Volantis (ζ Vol, ζ Volantis) is a binary star^[9] system in the southern constellation of Volans. It has an apparent visual magnitude of 3.93,^[2] which is bright enough to be seen with the naked eye. Based upon parallax measurements, it is approximately 141 light years from the Sun.^[1] The companion is a magnitude 9.7 star at an angular separation of 16.7″.^[9] Based upon their motion through space, this system made its perihelion passage some 858,000 years ago when it came within 22 ly (6.6 pc) of the Sun.^[10] It is currently moving away with a radial velocity of 48 km/s.^[4]

The primary component is K-type giant star with a stellar classification of K0 III.^[3] It has a derived luminosity of around 53 times that of the Sun.^[6] The measured angular diameter of this star is 2.32±0.06 mas.^[11] At the estimated distance of Zeta Volantis,^[11] this yields a physical size of about 11 times the radius of the Sun.^[5] The expanded outer envelope has an effective temperature of 4,721 K,^[7] giving it the orange glow of a K-type star.^[12]

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.
2. Cousins, A. W. J. (1977), "UCBV Magnitudes and Colours of South Circumpolar Stars", South African Astronomical Observatory Circulars, 1: 51, Bibcode:1977SAAOC...1...51C.
3. Houk, Nancy; Cowley, A. P. (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
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, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065.
5. Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1.. The radius (R_*) is given by:

   ${\displaystyle {\begin{aligned}2\cdot R_{*}&={\frac {(43.2\cdot 2.32\cdot 10^{-3})\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 21.6\cdot R_{\bigodot }\end{aligned}}}$

6. 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.
7. Alves, S.; et al. (April 2015), "Determination of the spectroscopic stellar parameters for 257 field giant stars", Monthly Notices of the Royal Astronomical Society, 448 (3): 2749−2765, arXiv:1503.02556, Bibcode:2015MNRAS.448.2749A, doi:10.1093/mnras/stv189.
8. "zet Vol -- High proper-motion Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-09-05.
9. 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.
10. Bailer-Jones, C. A. L. (March 2015), "Close encounters of the stellar kind", Astronomy & Astrophysics, 575: 13, arXiv:1412.3648, Bibcode:2015A&A...575A..35B, doi:10.1051/0004-6361/201425221, A35.
11. Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431: 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.
12. "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, retrieved 2012-01-16.