Beta Fornacis

Beta Fornacis (Beta For, β Fornacis, β For) is solitary^[8] star in the southern constellation of Fornax. It is visible to the naked eye with an apparent visual magnitude of 4.46.^[2] Based upon an annual parallax shift of 18.46 mas,^[1] it is located around 177 light years away from the Sun. At that distance, the visual magnitude is reduced by an interstellar extinction factor of 0.1.^[6]

β Fornacis

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Fornax
Right ascension	02h 49m 05.41890s[1]
Declination	−32° 24′ 21.2320″[1]
Apparent magnitude (V)	4.46[2]
Characteristics
Spectral type	G8 III[3]
U−B color index	+0.69[2]
B−V color index	+0.99[2]
R−I color index	+0.54
Astrometry
Radial velocity (Rv)	+17.56±0.12[1] km/s
Proper motion (μ)	RA: +86.023 mas/yr[1] Dec.: +159.404 mas/yr[1]
Parallax (π)	18.4596 ± 0.1024 mas[1]
Distance	176.7 ± 1.0 ly (54.2 ± 0.3 pc)
Absolute magnitude (MV)	0.894[4]
Details[5]
Mass	1.33±0.01 M☉
Radius	10.45±0.07 R☉
Luminosity	51.3±0.7 L☉
Surface gravity (log g)	2.67±0.10 cgs
Temperature	4,790±50 K
Metallicity [Fe/H]	−0.34±0.10 dex
Rotational velocity (v sin i)	2.19[6] km/s
Age	3.27±0.02 Gyr
Other designations
β For, CD−32° 1025, FK5 101, HD 17652, HIP 13147, HR 841, NLTT 9066, SAO 193931, WDS 02491-3224A.[7]
Database references
SIMBAD	data

This is an evolved, G-type giant star with a stellar classification of G8 III.^[3] It is a red clump giant, which means it has undergone helium flash and is currently generating energy through the fusion of helium at its core.^[9][4] Beta Fornacis has 1.33 times the mass of the Sun and, at an age of 3.3 billion years, has expanded to 10.5 times the Sun's radius. It is radiating 51 times the solar luminosity from its outer atmosphere at an effective temperature of 4,790 K.^[5]

Beta Fornacis has a visual companion, CCDM J02491-3224B, which has an apparent visual magnitude of approximately 14.0. As of 1928, it lay at an angular separation of 4.80 arc seconds along a position angle of 67°.^[10] Located around three degrees to the southwest is the globular cluster NGC 1049.^[11]

References

1. Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
2. Johnson, H. L.; et al. (1999), "UBVRIJKL photometry of the bright stars", Commission Lunar and Planetary Laboratory, 4: 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. Liu, Y. J.; et al. (2007), "The abundances of nearby red clump giants", Monthly Notices of the Royal Astronomical Society, 382 (2): 553–66, Bibcode:2007MNRAS.382..553L, doi:10.1111/j.1365-2966.2007.11852.x.
5. Gallenne, A.; Pietrzyński, G.; Graczyk, D.; Nardetto, N.; Mérand, A.; Kervella, P.; Gieren, W.; Villanova, S.; Mennickent, R. E.; Pilecki, B. (2018-08-01), "Fundamental properties of red-clump stars from long-baseline H-band interferometry", Astronomy & Astrophysics, 616: A68, arXiv:1806.09572, doi:10.1051/0004-6361/201833341, ISSN 0004-6361.
6. Jones, M. I.; et al. (2011), "Study of the impact of the post-MS evolution of the host star on the orbits of close-in planets", Astronomy & Astrophysics, 536: A71, arXiv:1110.6459, Bibcode:2011A&A...536A..71J, doi:10.1051/0004-6361/201117887, S2CID 55769003.
7. "* bet For". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-01-21.
8. 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.
9. Kubiak, M.; McWilliam, A.; Udalski, A.; Gorski, K. (June 2002), "Metal Abundance of Red Clump Stars in Baade's Window", Acta Astronomica, 52: 159–175, Bibcode:2002AcA....52..159K.
10. Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.
11. Plotner, Tammy (2007), The Night Sky Companion: A Yearly Guide to Sky-Watching 2008-2009, The Patrick Moore Practical Astronomy Series, Springer Science & Business Media, p. 617, ISBN 978-0387716091.