Astronomy:Gamma2 Fornacis

From HandWiki
Short description: Star in the constellation Fornax


γ2 Fornacis
Fornax constellation map.svg
Red circle.svg
Location of γ2 Fornacis (circled)
Observation data
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[1] mas
Distance520 ± 10 ly
(158 ± 3 pc)
Absolute magnitude (MV)−0.35[5]
Details
Mass2.40+0.44
−0.38
[2] M
Radius4.488[7] R
Luminosity117.073±0.111[7] L
Surface gravity (log g)3.50±0.25[2] cgs
Temperature9,000±500[2] K
Metallicity [Fe/H]−0.02[8] dex
Rotational velocity (v sin i)149[3] km/s
Age401+138
−170
[2] Myr
Other designations
γ2 For, CD−28°903, HD 17729, HIP 13202, HR 845, SAO 168082[9]
Database references
SIMBADdata

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]

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. 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Gullikson, Kevin et al. (2016). "The Close Companion Mass-ratio Distribution of Intermediate-mass Stars". The Astronomical Journal 152 (2): 40. doi:10.3847/0004-6256/152/2/40. Bibcode2016AJ....152...40G. 
  3. 3.0 3.1 3.2 Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics 537: A120. doi:10.1051/0004-6361/201117691. Bibcode2012A&A...537A.120Z. 
  4. 4.0 4.1 Houk, N. (1982). Michigan Catalogue of Two-dimensional Spectral Types for the HD stars. Declinations -40_ƒ0 to -26_ƒ0. 3. Bibcode1982mcts.book.....H. 
  5. 5.0 5.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A. 
  6. 6.0 6.1 Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. Bibcode2006AstL...32..759G. 
  7. 7.0 7.1 7.2 7.3 McDonald, I. et al. (2017). "Fundamental parameters and infrared excesses of Tycho-Gaia stars". Monthly Notices of the Royal Astronomical Society 471 (1): 770. doi:10.1093/mnras/stx1433. Bibcode2017MNRAS.471..770M. 
  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. doi:10.1051/0004-6361/201935765. Bibcode2019A&A...628A..94A. 
  9. "gam02 For". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=gam02+For. 
  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. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode2008MNRAS.389..869E. 
  11. Sinnott, Roger W.; Perryman, Michael A. C. (1997). Millennium Star Atlas. 1. Sky Publishing Corporation and the European Space Agency. p. 381. ISBN 0-933346-84-0.