47 Tauri
47 Tauri (abbreviated to 47 Tau) is a binary star in the zodiac constellation of Taurus. Parallax measurements made by the Hipparcos spacecraft put it at a distance of about 330 light-years (102 parsecs) from Earth. The system has a combined apparent magnitude of about 4.89,[2] meaning it can be faintly seen with the naked eye, according to the Bortle scale.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Taurus |
| Right ascension | 04h 13m 56.38482s[1] |
| Declination | +09° 15′ 49.7729″[1] |
| Apparent magnitude (V) | 4.89[2] (5.05 + 7.32)[3] |
| Characteristics | |
| Spectral type | G5III + A7V:[4] |
| U−B color index | +0.46[5] |
| B−V color index | +0.82[5] |
| Astrometry | |
| Radial velocity (Rv) | -8.2 ± 0.4[6] km/s |
| Proper motion (μ) | RA: -10.31[1] mas/yr Dec.: -30.01[1] mas/yr |
| Parallax (π) | 9.83 ± 0.64[1] mas |
| Distance | 330 ± 20 ly (102 ± 7 pc) |
| Orbit[3] | |
| Period (P) | 479 yr |
| Semi-major axis (a) | 1.053″ |
| Eccentricity (e) | 0.910 |
| Inclination (i) | 128.6° |
| Longitude of the node (Ω) | 52.9° |
| Periastron epoch (T) | B 1816.6 |
| Argument of periastron (ω) (secondary) | 263.0° |
| Details | |
| 47 Tau A | |
| Radius | 12.9[7] R☉ |
| Surface gravity (log g) | 2.67 ± 0.11[6] cgs |
| Temperature | 5117 ± 58[6] K |
| Metallicity [Fe/H] | -0.10 ± 0.08[6] dex |
| Other designations | |
| Database references | |
| SIMBAD | 47 Tau |
| 47 Tau A | |
| 47 Tau B | |
47 Tauri is a visual binary, meaning that the two components can be resolved, and the orbit is derived from the positions of the two stars. The primary component is a G-type giant. Its radius is about 13 times that of the Sun.[7] The companion is likely a white-colored A-type main-sequence star that is fainter. The two stars are separated about 1.3 arcseconds away,[2] and because of their large separation, the two stars take some 479 years to complete an orbit.[3]
References
- van Leeuwen, F.; et al. (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.
- "* 47 Tau". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2 May 2017.
- "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Retrieved 2 May 2017.
- Stephenson, C. B.; Sanwal, N. B. (1969). "The masses of stars above the main sequence". The Astronomical Journal. 74: 689. Bibcode:1969AJ.....74..689S. doi:10.1086/110845.
- Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
- Kang, Wonseok; Lee, Sang-Gak; Kim, Kang-Min (2011). "Abundances of Refractory Elements for G-Type Stars with Extrasolar Planets". The Astrophysical Journal. 736 (2): 87. arXiv:1105.3083. Bibcode:2011ApJ...736...87K. doi:10.1088/0004-637X/736/2/87. S2CID 118382154.
- Pasinetti Fracassini, L. E.; et al. (2001). "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics". Astronomy & Astrophysics. 367 (2): 521–24. arXiv:astro-ph/0012289. Bibcode:2001A&A...367..521P. doi:10.1051/0004-6361:20000451. S2CID 425754.