OU Geminorum
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Gemini |
| Right ascension | 06h 26m 10.2464s[2] |
| Declination | +18° 45′ 24.896″[2] |
| Apparent magnitude (V) | 6.768[3] |
| Characteristics | |
| Spectral type | K3Vk[3] |
| U−B color index | 0.662[3] |
| B−V color index | 0.972[3] |
| Variable type | BY Dra[4] |
| Astrometry | |
| Radial velocity (Rv) | −8.98±0.10[5] km/s |
| Proper motion (μ) | RA: −124.020±0.097[2] mas/yr Dec.: −159.335±0.054[2] mas/yr |
| Parallax (π) | 68.46 ± 0.34 mas[2] |
| Distance | 47.6 ± 0.2 ly (14.61 ± 0.07 pc) |
| Absolute magnitude (MV) | 5.93±0.05[3] |
| Orbit[5] | |
| Primary | OU Gem Aa |
| Companion | OU Gem Ab |
| Period (P) | 6.991878±0.000004 d |
| Eccentricity (e) | 0.151±0.0024 |
| Periastron epoch (T) | 54900.0719±0.0203 JD |
| Argument of periastron (ω) (secondary) | 77.63±1.09° |
| Semi-amplitude (K1) (primary) | 57.09±0.15 km/s |
| Semi-amplitude (K2) (secondary) | 66.22±0.28 km/s |
| Details[6] | |
| OU Gem Aa | |
| Mass | 0.85 M☉ |
| Radius | 0.81 R☉ |
| Surface gravity (log g) | 4.55 cgs |
| Temperature | 4960 K |
| OU Gem Ab | |
| Mass | 0.71 M☉ |
| Radius | 0.65 R☉ |
| Surface gravity (log g) | 4.65 cgs |
| Temperature | 4390 K |
| Other designations | |
| Database references | |
| SIMBAD | data |
OU Geminorum (OU Gem) is a visual binary or possible triple star located in the constellation of Gemini.
The system has an absolute magnitude of 5.93, so at a distance of 48 light years it has an apparent magnitude of 6.77 when viewed from earth. It also has a total proper motion of 0.210"/yr and belongs to the Ursa Major stream.
The system is a much studied BY Draconis variable star with a period of 6.99 days.[4] The primary star has a spectral type of K3Vk. The secondary star in the system has a surface temperature of 4486±50 K and orbits the primary in about seven days.[8][9]
References
[edit]- ^ Bopp, B. W.; Noah, P.; Klimke, A.; Hall, D. S.; Henry, G. W. (August 1981). "Photometry of HD 45088 : a new bright BY DRA variable". Publications of the Astronomical Society of the Pacific. 93: 504–506. Bibcode:1981PASP...93..504B. doi:10.1086/130867. S2CID 122130492.
- ^ a b c d e Brown, A. G. A.; et al. (2016). "Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties". Astronomy and Astrophysics. 595. A2. arXiv:1609.04172. Bibcode:2016A&A...595A...2G. doi:10.1051/0004-6361/201629512. hdl:2445/125903. S2CID 1828208.Gaia Data Release 1 catalog entry
- ^ a b c d e Koen, C.; et al. (April 2010). "UBV(RI)C JHK observations of Hipparcos-selected nearby stars". Monthly Notices of the Royal Astronomical Society. 403 (4): 1949–1968. Bibcode:2010MNRAS.403.1949K. doi:10.1111/j.1365-2966.2009.16182.x.
- ^ a b Bopp, B. W. (1980). "HD 45088 as a BY Draconis variable". Publications of the Astronomical Society of the Pacific. 92: 218–220. Bibcode:1980PASP...92..218B. doi:10.1086/130651. S2CID 119915971.
- ^ a b Glazunova, L. V.; et al. (2014). "Absolute parameters and chemical composition of the binary star OU Gem". Monthly Notices of the Royal Astronomical Society. 444 (2): 1901–1908. Bibcode:2014MNRAS.444.1901G. doi:10.1093/mnras/stu1576.
- ^ Fuhrmann, Klaus (2008). "Nearby stars of the Galactic disc and halo - IV". Monthly Notices of the Royal Astronomical Society. 384 (1): 173–224. Bibcode:2008MNRAS.384..173F. doi:10.1111/j.1365-2966.2007.12671.x.
- ^ "V* OU Gem". SIMBAD. Centre de données astronomiques de Strasbourg.
- ^ "Aricns 4C00500". Archived from the original on 2012-09-07. Retrieved 2011-10-04.
- ^ "Multiwavelength optical observations of chromospherically active bina…" (PDF). Archived from the original (PDF) on 2012-12-09.
External links
[edit]- Luck, R. Earle (February 2005). "Stars within 15 Parsecs: Abundances for a Northern Sample". The Astronomical Journal. 129 (2): 1063–1083. Bibcode:2005AJ....129.1063L. doi:10.1086/427250.
- Innes, T.V.; et al. (1998). "OU Gem and AT Cap IN 1984/5 (Commissions 27 and 42 of the IAU)". Information Bulletin on Variable Stars. 4569: 1. Bibcode:1998IBVS.4569....1I.
- Mishenina, T.V.; et al. (2010). "The New Absolute Parameters Of Ou Gem – The star Of By Dra Type". Odessa Astronomical Publications. 23: 83. Bibcode:2010OAP....23...83M.
- University of Hamburg, The. "NEXXUS - Search the Gliese Catalogue". Retrieved 3 October 2011.
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