Nu Geminorum, Latinized from ν Geminorum, is a triple[5] star system in the constellation Gemini. It has an apparent visual magnitude of 4.16,[2] which is bright enough to be visible to the naked eye on a dark night. Based upon an annual parallax shift of 5.99 mas,[1] it is located at a distance of roughly 540 light years from the Sun. The position of this system near the ecliptic means it is subject to lunar occultations.[9]
 ν Geminorum in optical light | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Gemini |
| Right ascension | 06h 28m 57.78613s[1] |
| Declination | +20° 12′ 43.6856″[1] |
| Apparent magnitude (V) | 4.16[2] |
| Characteristics | |
| Spectral type | B6 III + B8 III[3] |
| U−B color index | −0.47[2] |
| B−V color index | −0.13[2] |
| Astrometry | |
| Radial velocity (Rv) | +39.4[4] km/s |
| Proper motion (μ) | RA: −6.82[1] mas/yr Dec.: −13.10[1] mas/yr |
| Parallax (π) | 5.99 ± 0.28 mas[1] |
| Distance | 540 ± 30 ly (167 ± 8 pc) |
| Absolute magnitude (MV) | −2.2 + −1.2[3] |
| Orbit[5] | |
| Primary | ν Gem Aa |
| Companion | ν Gem Ab |
| Period (P) | 53.7722 ± 0.0008 d |
| Semi-major axis (a) | 2.82 ± 0.02 mas |
| Eccentricity (e) | 0.056 ± 0.003 |
| Inclination (i) | 0.98 ± 0.03° |
| Longitude of the node (Ω) | 78.9 ± 0.2° |
| Periastron epoch (T) | MJD 51011.8 ± 0.1 |
| Argument of periastron (ω) (secondary) | 6.7 ± 2.0° |
| Semi-amplitude (K1) (primary) | 51.6 ± 0.6 km/s |
| Semi-amplitude (K2) (secondary) | 52.5 ± 1.1 km/s |
| Orbit[5] | |
| Primary | ν Gem A |
| Companion | ν Gem B |
| Period (P) | 6977.3 ± 6.1 |
| Semi-major axis (a) | 82.8 ± 1.3 mas |
| Eccentricity (e) | 0.241 ± 0.002 |
| Inclination (i) | 75.9 ± 0.2° |
| Longitude of the node (Ω) | 121.0 ± 0.1° |
| Periastron epoch (T) | MJD 48810.3 ± 13.0 |
| Argument of periastron (ω) (secondary) | 226.9 ± 0.4° |
| Semi-amplitude (K1) (primary) | 8.0 ± 0.1 km/s |
| Semi-amplitude (K2) (secondary) | 15.9 ± 0.1 km/s |
| Details | |
| ν Gem Aa | |
| Mass | 3.34[5] M☉ |
| Luminosity | 1,380[6] L☉ |
| Temperature | 14,100[6] K |
| Rotational velocity (v sin i) | 160[7] km/s |
| ν Gem Ab | |
| Mass | 3.28[5] M☉ |
| ν Gem B | |
| Mass | 3.33[5] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
The inner components of this multiple star system have an orbital period of about 54 days and a nearly circular orbit with an eccentricity of 0.056.[5] There is some uncertainty in the spectral type, with classifications ranging from a main sequence star to a giant. Orbiting the inner pair is a classical Be star, with an orbital period of 19.1 years and an eccentricity of 0.24.[5] The two orbits are co-directional and roughly coplanar. The system is overall dynamically stable, and shows no signs of Kozai-Lidov cycles. The outer Be star appears to be single.[5]
According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, this star was titled as Nucatai.[10]
References edit
- ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
- ^ a b c d Crawford, D. L.; et al. (1971), "Four-color, H-beta, and UBV photometry for bright B-type stars in the northern hemisphere", The Astronomical Journal, 76: 1058, Bibcode:1971AJ.....76.1058C, doi:10.1086/111220.
- ^ a b Cvetković, Z.; Ninković, S. (November 2008), "Orbits for two short-period and two long-period binaries", New Astronomy, 13 (8): 587–592, Bibcode:2008NewA...13..587C, doi:10.1016/j.newast.2008.03.005.
- ^ Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Carnegie Institute of Washington D.C., Bibcode:1953GCRV..C......0W.
- ^ a b c d e f g h i Klement, Robert; Hadrava, Petr; Rivinius, Thomas; Baade, Dietrich; Cabezas, Mauricio; Heida, Marianne; Schaefer, Gail H.; Gardner, Tyler; Gies, Douglas R.; Anugu, Narsireddy; Lanthermann, Cyprien; Davies, Claire L.; Anderson, Matthew D.; Monnier, John D.; Ennis, Jacob; Labdon, Aaron; Setterholm, Benjamin R.; Kraus, Stefan; Ten Brummelaar, Theo A.; Le Bouquin, Jean-Baptiste (2021). "ν Gem: A Hierarchical Triple System with an Outer Be Star". The Astrophysical Journal. 916 (1): 24. arXiv:2105.13437. Bibcode:2021ApJ...916...24K. doi:10.3847/1538-4357/ac062c. S2CID 235247900.
- ^ a b Hohle, M. M.; et al. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten, 331 (4): 349, arXiv:1003.2335, Bibcode:2010AN....331..349H, doi:10.1002/asna.200911355, S2CID 111387483.
- ^ Abt, Helmut A.; et al. (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode:2002ApJ...573..359A, doi:10.1086/340590.
- ^ "nu. Gem". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-12-06.
{{cite web}}: CS1 maint: postscript (link) - ^ Blow, G. L.; et al. (November 1982), "Photoelectric observations of lunar occultations. XIII", Astronomical Journal, 87: 1571–1584, Bibcode:1982AJ.....87.1571B, doi:10.1086/113247.
- ^ Rhoads, Jack W. (November 15, 1971), Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars (PDF), California Institute of Technology: Jet Propulsion Laboratory, retrieved 2019-01-09.
External links edit
- Kaler, James B. (January 26, 2007), "Nu Geminorum", stars, University of Illinois, retrieved 2016-12-07.