| 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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Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction