Astronomy:Eta Reticuli
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Reticulum |
| Right ascension | 04h 21m 53.32714s[1] |
| Declination | −63° 23′ 11.0072″[1] |
| Apparent magnitude (V) | 5.22[2] |
| Characteristics | |
| Spectral type | G7 III[3] |
| U−B color index | +0.62[2] |
| B−V color index | +0.945[2] |
| Astrometry | |
| Radial velocity (Rv) | +45.0±0.8[4] km/s |
| Proper motion (μ) | RA: +85.56[1] mas/yr Dec.: +174.62[1] mas/yr |
| Parallax (π) | 8.48 ± 0.18[1] mas |
| Distance | 385 ± 8 ly (118 ± 3 pc) |
| Absolute magnitude (MV) | +1.28[5] |
| Details[6] | |
| Mass | 2.54 M☉ |
| Radius | 12[7] R☉ |
| Luminosity | 120 L☉ |
| Surface gravity (log g) | 2.49 cgs |
| Temperature | 4,951±48 K |
| Metallicity [Fe/H] | −0.15±0.03[8] dex |
| Age | 1.17 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Eta Reticuli, Latinized from η Reticuli, is a solitary[10] star in the southern constellation of Reticulum. With an apparent visual magnitude of 5.22,[2] it is faintly visible to the naked eye on a dark night. Based upon an annual parallax shift of 8.48 mas,[1] it is located at a distance of roughly 385 light years from the Sun. It may be a member of the high-velocity Zeta Herculis Moving Group of stars that share a common motion through space.[5]
This is an evolved G-type giant star with a stellar classification of G7 III.[3] Based upon stellar models, it has an estimated 2.54[6] times the mass of the Sun and 13.24[7] times the Sun's radius. With an age of around 1.17 billion years, it is radiating 120 times the solar luminosity from its outer atmosphere at an effective temperature of 4,948 K.[6]
Eta Reticuli is moving through the Galaxy at a speed of 117.6 km/s relative to the Sun. Its projected Galactic orbit carries it between 11,700 and 31,600 light years from the center of the Galaxy.[11]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 2.3 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, Bibcode: 1986EgUBV........0M.
- ↑ 3.0 3.1 Houk, Nancy; Cowley, A. P. (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode: 1978mcts.book.....H.
- ↑ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics 546: 14, doi:10.1051/0004-6361/201219219, A61, Bibcode: 2012A&A...546A..61D.
- ↑ 5.0 5.1 Eggen, O. J. (1958), "Stellar groups. II. The ζ Herculis, ɛ Indi and 61 Cygni groups of high-velocity stars", Monthly Notices of the Royal Astronomical Society 118 (2): 154, doi:10.1093/mnras/118.2.154, Bibcode: 1958MNRAS.118..154E.
- ↑ 6.0 6.1 6.2 Luck, R. Earle (September 2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal 150 (3): 23, doi:10.1088/0004-6256/150/3/88, 88, Bibcode: 2015AJ....150...88L.
- ↑ 7.0 7.1 Pasinetti Fracassini, L. E. et al. (2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy & Astrophysics 367 (2): 521–24, doi:10.1051/0004-6361:20000451, Bibcode: 2001A&A...367..521P.
- ↑ Alves, S. et al. (April 2015), "Determination of the spectroscopic stellar parameters for 257 field giant stars", Monthly Notices of the Royal Astronomical Society 448 (3): 2749–2765, doi:10.1093/mnras/stv189, Bibcode: 2015MNRAS.448.2749A.
- ↑ "eta Ret". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=eta+Ret.
- ↑ 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, Bibcode: 2008MNRAS.389..869E.
- ↑ Eta Reticuli (HIP 20384)
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