λ Normae, Latinised as Lambda Normae, is a binary star[3] system in the southern constellation of Norma, located near the northern constellation boundary with Scorpius. It is visible to the naked eye as a dim, white-hued point of light that shines with a combined apparent visual magnitude of 5.44.[2] The system is located approximately 350 light years distant from the Sun based on parallax, but is drifting closer with a radial velocity of about −15 km/s.[2]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Norma |
| Right ascension | 16h 19m 17.64660s[1] |
| Declination | −42° 40′ 26.3014″[1] |
| Apparent magnitude (V) | 5.44[2] (5.83 + 6.86)[3] |
| Characteristics | |
| Spectral type | A0V + A3V |
| B−V color index | 0.099±0.004[2] |
| Astrometry | |
| Radial velocity (Rv) | −15.0±3.7[2] km/s |
| Proper motion (μ) | RA: +7.59[1] mas/yr Dec.: −13.30[1] mas/yr |
| Parallax (π) | 9.35 ± 0.76 mas[1] |
| Distance | 350 ± 30 ly (107 ± 9 pc) |
| Absolute magnitude (MV) | 0.31[2] |
| Orbit[3] | |
| Period (P) | 67.50 yr |
| Semi-major axis (a) | 0.293″ |
| Eccentricity (e) | 0.788 |
| Inclination (i) | 45.8° |
| Longitude of the node (Ω) | 215.2° |
| Periastron epoch (T) | 2049.59 B |
| Argument of periastron (ω) (secondary) | 82.5° |
| Details | |
| Luminosity | 64[2] L☉ |
| λ Nor A | |
| Mass | 2.53–2.57[4] M☉ |
| λ Nor B | |
| Mass | 2.00–2.13[4] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
The pair have an orbital period of 67.5 years with a high eccentricity of 0.788.[3] Both components are A-type main-sequence stars that are generating energy through core hydrogen fusion. The primary component has a visual magnitude of 5.83, and is of class A0V. The fainter secondary is class A3V with a magnitude 6.86.[6]
References
edit- ^ a b c d e 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.
- ^ a b c d e f g 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.
- ^ a b c d "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Archived from the original on 1 August 2017. Retrieved 16 May 2017.
- ^ a b Cvetkovic, Z.; Ninkovic, S. (2010), "On the Component Masses of Visual Binaries", Serbian Astronomical Journal, 180 (180): 71–80, Bibcode:2010SerAJ.180...71C, doi:10.2298/SAJ1080071C
- ^ "lam Nor". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 31 March 2015.
- ^ last, O. Yu.; Tamazian, V. S.; Docobo, J. A.; Chulkov, D. A. (2012). "Dynamical masses of a selected sample of orbital binaries". Astronomy & Astrophysics. 546: 5. Bibcode:2012A&A...546A..69M. doi:10.1051/0004-6361/201219774. A69.