Delta Fornacis

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δ Fornacis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Fornax
Right ascension 03h 42m 14.90248s[1]
Declination −31° 56′ 18.1055″[1]
Apparent magnitude (V) 5.00[2]
Spectral type B5 III[3]
U−B color index −0.60[2]
B−V color index −0.16[2]
Radial velocity (Rv) +26.00[4] km/s
Proper motion (μ) RA: +4.80[1] mas/yr
Dec.: +13.64[1] mas/yr
Parallax (π) 3.85 ± 0.25[1] mas
Distance 850 ± 60 ly
(260 ± 20 pc)
Mass 5.9±0.2[5] M
Radius 6.0[6] R
Luminosity 1,291[7] L
Temperature 16,230±930[8] K
Rotational velocity (v sin i) 185[9] km/s
Age 63.1±16.1[5] Myr
Other designations
δ For, CD−32° 1430, FK5 133, HD 23227, HIP 17304, HR 1134, SAO 194467.[10]
Database references

Delta Fornacis (δ For) is a solitary[11] star near the middle of the southern constellation of Fornax. With an apparent visual magnitude of 5.00,[2] it is faintly visible to the naked eye. The star has an annual parallax shift of 3.85 mas,[1] indicating it lies at a distance of roughly 850 light years from the Sun.

This is an evolved B-type giant star with a stellar classification of B5 III[3] It has an angular diameter of 0.215±0.015 mas,[8] which, at the estimated distance of the star, yields a physical size of around 6 times the radius of the Sun.[6] Around 63 million years old,[5] the star is spinning rapidly with a projected rotational velocity of 185 km/s.[9] It has an estimated 5.9[5] times the Sun's mass and radiates 1,291[7] times the solar luminosity from its outer atmosphere at an effective temperature of 16,230 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 Johnson, H. L.; Iriarte, B.; Mitchell, R. I.; Wisniewskj, W. Z. (1999), "UBVRIJKL photometry of the bright stars", Commission Lunar and Planetary Laboratory, 4: 99, Bibcode:1966CoLPL...4...99J. 
  3. ^ a b Houk, N. (1982), Michigan catalogue of two-dimensional spectral types for the HD stars, 3, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1982MSS...C03....0H. 
  4. ^ Kharchenko, N. V.; et al. (2007), "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ˜55000 stars and mean radial velocities of 516 Galactic open clusters and associations", Astronomische Nachrichten, 328 (9): 889, Bibcode:2007AN....328..889K, arXiv:0705.0878Freely accessible, doi:10.1002/asna.200710776. 
  5. ^ a b c d Tetzlaff, N.; et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, Bibcode:2011MNRAS.410..190T, arXiv:1007.4883Freely accessible, doi:10.1111/j.1365-2966.2010.17434.x. 
  6. ^ a b 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:
  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 Zorec, J.; et al. (2009). "Fundamental parameters of B supergiants from the BCD system. I. Calibration of the (λ_1, D) parameters into Teff". Astronomy and Astrophysics. 501 (1): 297–320. Bibcode:2009A&A...501..297Z. arXiv:0903.5134Freely accessible. doi:10.1051/0004-6361/200811147. 
  9. ^ a b Abt, Helmut A.; et al. (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode:2002ApJ...573..359A, doi:10.1086/340590. 
  10. ^ "del For -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-01-21. 
  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.