Astronomy:Sigma2 Tauri
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Taurus |
| Right ascension | 04h 39m 16.50230s[1] |
| Declination | +15° 55′ 04.7029″[1] |
| Apparent magnitude (V) | 4.70[2] |
| Characteristics | |
| Spectral type | A5 Vn[3] |
| U−B color index | +0.13[2] |
| B−V color index | +0.14[2] |
| Astrometry | |
| Radial velocity (Rv) | +40.8±1.2[4] km/s |
| Proper motion (μ) | RA: +83.17[1] mas/yr Dec.: −20.97[1] mas/yr |
| Parallax (π) | 20.97 ± 0.27[1] mas |
| Distance | 156 ± 2 ly (47.7 ± 0.6 pc) |
| Details | |
| Mass | 1.71[5] M☉ |
| Radius | 1.9[6] R☉ |
| Luminosity | 22.5[7] L☉ |
| Surface gravity (log g) | 3.96[5] cgs |
| Temperature | 8,165±278[5] K |
| Metallicity [Fe/H] | 0.10±0.11[8] dex |
| Rotational velocity (v sin i) | 128[3] km/s |
| Age | 258[5] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Sigma2 Tauri (σ2 Tauri) is the Bayer designation for a white-hued star in the zodiac constellation of Taurus. It has an apparent visual magnitude of +4.70,[2] which indicates it is visible to the naked eye. Based upon parallax measurements, σ2 Tauri is about 156 light-years distant.
σ2 Tauri is a solitary[10] A-type main sequence star with a stellar classification of A5 Vn.[3] The 'n' suffix indicates the lines are "nebulous" due to rapid rotation, and indeed it is spinning with a projected rotational velocity of 128 km/s.[3] The star is an estimated 258[5] million years old, with 1.7[5] times the mass of the Sun. It is radiating 22.5[7] times the Sun's luminosity from its photosphere at an effective temperature of around 8,165 K.[5] The star is considered a member of the Hyades cluster.[6]
In Chinese astronomy, σ2 Tauri is called 附耳, Pinyin: Fùěr, meaning Whisper, because this star is marking itself and stands alone in the Whisper asterism of the Net mansion (see: Chinese constellation).[11]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 2.3 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode: 1966CoLPL...4...99J.
- ↑ 3.0 3.1 3.2 3.3 Royer, F. et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics 463 (2): 671–682, doi:10.1051/0004-6361:20065224, Bibcode: 2007A&A...463..671R.
- ↑ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics 546: 14, doi:10.1051/0004-6361/201219219, A61, Bibcode: 2012A&A...546A..61D.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal 804 (2): 146, doi:10.1088/0004-637X/804/2/146, Bibcode: 2015ApJ...804..146D.
- ↑ 6.0 6.1 Pasinetti Fracassini, L. E. et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics 367: 521–524, doi:10.1051/0004-6361:20000451, Bibcode: 2001A&A...367..521P.
- ↑ 7.0 7.1 McDonald, I. et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–57, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode: 2012MNRAS.427..343M.
- ↑ Soubiran, C. et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics 515: A111, doi:10.1051/0004-6361/201014247, Bibcode: 2010A&A...515A.111S.
- ↑ "sig02 Tau". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=sig02+Tau.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Script error: The function "in_lang" does not exist. AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 23 日
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