λ1 Fornacis, Latinized as Lambda1 Fornacis, is a red giant star in the southern constellation of Fornax. It is just visible to the naked eye as a dim, yellow-hued point of light with an apparent visual magnitude of 5.91. The star is located 383 light years from the Sun, based on stellar parallax, and is drifting further away with a radial velocity of +10 km/s.

Lambda1 Fornacis
Location of Lambda1 Fornacis (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Fornax
Right ascension 02h 33m 07.0259s[1]
Declination −34° 38′ 59.882″[1]
Apparent magnitude (V) 5.91[2]
Characteristics
Evolutionary stage Horizontal branch[2]
Spectral type K0/1III[3]
U−B color index +2.14[4]
B−V color index +1.06[4]
Astrometry
Radial velocity (Rv)+10.29±0.14[1] km/s
Proper motion (μ) RA: −18.216±0.017[1] mas/yr
Dec.: −18.058±0.026[1] mas/yr
Parallax (π)8.5123 ± 0.0286 mas[1]
Distance383 ± 1 ly
(117.5 ± 0.4 pc)
Absolute magnitude (MV)0.67[5]
Details
Mass2.32[2] M
Radius12.38[2] R
Luminosity66[2] L
Surface gravity (log g)2.32[2] cgs
Temperature4,770[2] K
Metallicity [Fe/H]0.18±0.14[2] dex
Rotational velocity (v sin i)2.00[2] km/s
Other designations
λ1 For, CD–35°877, GC 3067, HD 15975, HIP 11867, HR 744, SAO 193763, PPM 278055, GCRV 53183[6]
Database references
SIMBADdata

λ1 Fornacis is a K-type giant star with a stellar classification of K0/1III, showing it has exhausted its core hydrogen and evolved away from the main sequence. It is currently on the horizontal branch, fusing helium in its core. The star has 2.3 times the mass of the Sun and 12 times its radius. It is radiating 66 times the luminosity of the Sun from its photosphere at an effective temperature of 4,770 K. The abundance of elements with mass higher than helium is similar to the Sun.

References

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  1. ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  2. ^ a b c d e f g h i Jones, M. I.; et al. (December 2011). "Study of the impact of the post-MS evolution of the host star on the orbits of close-in planets. I. Sample definition and physical properties". Astronomy & Astrophysics. 536: 7. arXiv:1110.6459. Bibcode:2011A&A...536A..71J. doi:10.1051/0004-6361/201117887. S2CID 55769003. A71.
  3. ^ Houk, N. (1982). "Michigan Catalogue of Two-dimensional Spectral Types for the HD stars. Volume_3. Declinations -40_ƒ0 to -26_ƒ0". Michigan Catalogue of Two-dimensional Spectral Types for the HD stars. Volume_3. Declinations -40_ƒ0 to -26_ƒ0. Bibcode:1982mcts.book.....H.
  4. ^ a b Nicolet, B. (1975). "Catalogue of Measurements in the Cape UBV Photometry on Magnetic Tape". Astronomy and Astrophysics Supplement Series. 22: 239. Bibcode:1975A&AS...22..239N.
  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. ^ "lam01 For". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-02-16.