Gamma2 Fornacis

Gamma² Fornacis, a name Latinized from γ² Fornacis, is a single^[10] star in the southern constellation Fornax. It has a white hue and is faintly visible to the naked eye at night with an apparent visual magnitude of 5.4.^[2] The distance to Gamma² Fornacis is approximately 520 light years based on parallax.^[1] It is drifting further away with a radial velocity of 24 km/s.^[6] Gamma¹ Fornacis is a 6th magnitude star about four degrees to the north.^[11]

For other stars with this Bayer designation, see γ Fornacis.

γ² Fornacis

Location of γ2 Fornacis (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Fornax
Right ascension	02h 49m 54.1822s[1]
Declination	−27° 56′ 31.123″[1]
Apparent magnitude (V)	5.389[2]
Characteristics
Evolutionary stage	Main sequence[3]
Spectral type	A1 V[4]
B−V color index	0.013±0.004[5]
Astrometry
Radial velocity (Rv)	24.0±4.2[6] km/s
Proper motion (μ)	RA: −47.053[1] mas/yr Dec.: 20.932[1] mas/yr
Parallax (π)	6.3134 ± 0.1330 mas[1]
Distance	520 ± 10 ly (158 ± 3 pc)
Absolute magnitude (MV)	−0.35[5]
Details
Mass	2.40+0.44 −0.38[2] M☉
Radius	4.488[7] R☉
Luminosity	117.073±0.111[7] L☉
Surface gravity (log g)	3.50±0.25[2] cgs
Temperature	9,000±500[2] K
Metallicity [Fe/H]	−0.02[8] dex
Rotational velocity (v sin i)	149[3] km/s
Age	401+138 −170[2] Myr
Other designations
γ2 For, CD−28°903, HD 17729, HIP 13202, HR 845, SAO 168082[9]
Database references
SIMBAD	data

The stellar classification of Gamma² Fornacis is A1 V,^[4] which is notation for an A-type main-sequence star that, like the Sun, is generating energy through core hydrogen fusion. Comparison of its properties to theoretical models suggest an age of about 400^[2] million years old. It has a high rate of spin, showing a projected rotational velocity of 149 km/s.^[3] The star has 2.4^[2] times the mass of the Sun and 4.5^[7] times the Sun's radius. It is radiating 117^[7] times the luminosity of the Sun from its photosphere at an effective temperature of roughly 9,000 K.^[2]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
2. Gullikson, Kevin; et al. (2016). "The Close Companion Mass-ratio Distribution of Intermediate-mass Stars". The Astronomical Journal. 152 (2): 40. arXiv:1604.06456. Bibcode:2016AJ....152...40G. doi:10.3847/0004-6256/152/2/40. S2CID 119179065.
3. Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics. 537: A120. arXiv:1201.2052. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691. S2CID 55586789.
4. Houk, N. (1982). Michigan Catalogue of Two-dimensional Spectral Types for the HD stars. Declinations -40_ƒ0 to -26_ƒ0. Vol. 3. Bibcode:1982mcts.book.....H.
5. Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
6. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
7. McDonald, I.; et al. (2017). "Fundamental parameters and infrared excesses of Tycho-Gaia stars". Monthly Notices of the Royal Astronomical Society. 471 (1): 770. arXiv:1706.02208. Bibcode:2017MNRAS.471..770M. doi:10.1093/mnras/stx1433.
8. Anders, F.; et al. (2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy and Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. S2CID 131780028.
9. "gam02 For". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-01-17.
10. 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.
11. Sinnott, Roger W.; Perryman, Michael A. C. (1997). Millennium Star Atlas. Vol. 1. Sky Publishing Corporation and the European Space Agency. p. 381. ISBN 0-933346-84-0.