| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Norma |
| Right ascension | 16 19 50.42227 |
| Declination | −50° 09′ 19.8223″ |
| Apparent magnitude (V) | 4.02 |
| Characteristics | |
| Spectral type | K0III |
| U−B color index | +1.16 |
| B−V color index | +1.08 |
| Astrometry | |
| Radial velocity (Rv) | −28.9±0.7 km/s |
| Proper motion (μ) | RA: −159.71 mas/yr Dec.: −52.25 mas/yr |
| Parallax (π) | 25.33 ± 0.20 mas |
| Distance | 129 ± 1 ly (39.5 ± 0.3 pc) |
| Absolute magnitude (MV) | 1.057 |
| Details | |
| Mass | 2.16 M☉ |
| Luminosity | 51 L☉ |
| Surface gravity (log g) | 2.80 cgs |
| Temperature | 4,699 K |
| Metallicity | 0.23 dex |
| Other designations | |
| γ Nor, CD−49° 10536, GC 12216, GJ 9554, HD 146686, HIP 80000, HR 6072, SAO 243643 | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
Gamma Normae, Latinized from γ Nor, is the brightest star in the southern constellation of Norma. Its apparent magnitude is 4.02 – making it a faint star but visible to the naked eye. Based upon an annual parallax shift of 25.33 mas as seen from Earth, this star is located roughly 129 light years from the Sun. It is moving closer to the Sun with a radial velocity of −29 km/s.
This is an evolved, yellow-hued giant of spectral type K0 III around 2.16 times as massive as the Sun that has swollen to a diameter 10 times that of the Sun. It is a red clump star on the horizontal branch, which indicates it is generating energy through helium fusion at its core. The star is radiating 51 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,699 K.
Gamma Normae is a close double, with a magnitude 10 companion. The pair has been previously identified as a binary star system, but the second release of Gaia data showed the companion star to be much more distant. Another 16-magnitude star, with a temperature of 5,972 K, is listed 20" away with nearly the same parallax and proper motion as Gamma Normae.
γ Nor is a yellow supergiant located nearby on the celestial sphere, but is much further away from Earth and nearly a magnitude fainter.
References
- ^ van Leeuwen, F. (2007). "Validation of the New Hipparcos Reduction". Astronomy and Astrophysics. 474 (2): 653–64. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
- ^ Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
- ^ Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
- ^ Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
- ^ 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.
- ^ 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.
- "* gam02 Nor". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 22 December 2012.
- Kaler, James B. "Gamma-2 Normae". Stars. University of Illinois. Retrieved 23 March 2015.
- Laney, C. D.; et al. (January 2012), "A new Large Magellanic Cloud K-band distance from precision measurements of nearby red clump stars", Monthly Notices of the Royal Astronomical Society, 419 (2): 1637–1641, arXiv:1109.4800, Bibcode:2012MNRAS.419.1637L, doi:10.1111/j.1365-2966.2011.19826.x, S2CID 117788450.
- 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.
- 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.
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