Gamma¹ Fornacis

Gamma¹ Fornacis, which is Latinized from γ¹ Fornacis, is a star in the constellation Fornax, positioned less than a degree south of the border with Eridanus.[6] The star has a golden hue and can be a challenge to view with the naked eye even in good seeing conditions, having an apparent visual magnitude of 6.15.[2] It is located at a distance of approximately 367 light years from the Sun based on parallax,[1] but is drifting closer with a radial velocity of −7 km/s.[4] The star has an absolute magnitude of +0.5.[4]

γ¹ Fornacis

Location of γ^1 Fornacis (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Fornax
Right ascension	02^h 49^m 50.96219^s[1]
Declination	−24° 33′ 37.1290″[1]
Apparent magnitude (V)	6.154[2]
Characteristics
Spectral type	G9 III[3]
B−V color index	1.081[2]
Astrometry
Radial velocity (Rv)	−6.58±0.64[4] km/s
Proper motion (μ)	RA: −51.603[1] mas/yr Dec.: −127.797[1] mas/yr
Parallax (π)	8.8835 ± 0.0576[1] mas
Distance	367 ± 2 ly (112.6 ± 0.7 pc)
Absolute magnitude (MV)	+0.52±0.21[4]
Details
Mass	1.65[2] M☉
Radius	10.44+0.73 −0.49[1] R☉
Luminosity	50.814±0.439[1] L☉
Surface gravity (log g)	2.60[4] cgs
Temperature	4,657±56[2] K
Metallicity [Fe/H]	−0.02[4] dex
Age	3.36[2] Gyr
Other designations
γ^1 For, CD−25°1120, GC 3404, HD 17713, HIP 13197, HR 844, SAO 168081, WDS J02498-2434A[5]
Database references
SIMBAD	data

The stellar classification of γ¹ Fornacis is G9 III,[3] which indicates this is an aging giant star[4] that has exhausted the supply of hydrogen at its core, then cooled and expanded away from the main sequence. It is an estimated 3.4[2] billion years old with a metallicity that is close to solar, indicating the abundances of heavy elements are similar to those in the Sun. It has 1.65[2] times the mass of the Sun and has expanded to ten[1] times the Sun's radius. The star is radiating 51[1] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,657 K.[2]

γ¹ Fornacis has three visual companions listed in the Washington Double Star Catalog. These are faint 11th - 13th magnitude stars at 11' - 56' distance from γ¹.[7] Gamma² Fornacis is a 5th magnitude star located four degrees to the south.[6]

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. Luck, R. Earle (2015). "Abundances in the Local Region. I. G and K Giants". Astronomical Journal. 150 (3). 88. arXiv:1507.01466. Bibcode:2015AJ....150...88L. doi:10.1088/0004-6256/150/3/88. S2CID 118505114.
3. Abt, Helmut A. (2008). "Visual Multiples. IX. MK Spectral Types". The Astrophysical Journal Supplement Series. 176: 216–217. Bibcode:2008ApJS..176..216A. doi:10.1086/525529.
4. Luck, R. Earle; Heiter, Ulrike (2007). "Giants in the Local Region". The Astronomical Journal. 133 (6): 2464. Bibcode:2007AJ....133.2464L. doi:10.1086/513194.
5. "gam01 For". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-01-16.
6. Sinnott, Roger W.; Perryman, Michael A. C. (1997). Millennium Star Atlas. 1. Sky Publishing Corporation and the European Space Agency. pp. 358, 381. ISBN 0-933346-84-0.
7. Mason, Brian D.; et al. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.