18 Tauri is a single[9] star in the zodiac constellation of Taurus, located 444 light years away from the Sun. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of 5.66.[2] The star is moving further from the Earth with a heliocentric radial velocity of +4.8.[5] It is a member of the Pleiades[10] open cluster, which is positioned near the ecliptic and thus is subject to lunar occultations.[11]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Taurus |
| Right ascension | 03h 45m 09.73954s[1] |
| Declination | +24° 50′ 21.3495″[1] |
| Apparent magnitude (V) | 5.66[2] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | B8 V[4] |
| B−V color index | −0.064±0.012[2] |
| Astrometry | |
| Radial velocity (Rv) | +4.8±0.8[5] km/s |
| Proper motion (μ) | RA: +20.744[1] mas/yr Dec.: −46.538[1] mas/yr |
| Parallax (π) | 7.3405 ± 0.1237 mas[1] |
| Distance | 444 ± 7 ly (136 ± 2 pc) |
| Absolute magnitude (MV) | 0.19[2] |
| Details | |
| Mass | 3.34±0.06[3] M☉ |
| Radius | 2.89[6] R☉ |
| Luminosity | 160+18 −15[3] L☉ |
| Surface gravity (log g) | 4.126±0.113[7] cgs |
| Temperature | 13,748±223[7] K |
| Rotational velocity (v sin i) | 212[3] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a B-type main-sequence star with a stellar classification of B8 V,[4] and is about halfway through its main sequence lifetime.[3] It displays an infrared excess, suggesting the presence of an orbiting debris disk with a black body temperature of 75 K at a separation of 137.8 AU from the host star.[6] The star has 3.34[3] times the mass of the Sun and 2.89[6] times the Sun's radius. It is radiating 160[3] times the Sun's luminosity from its photosphere at an effective temperature of 13,748 K.[7] 18 Tauri has a high rate of spin, showing a projected rotational velocity of 212 km/s.[3]
References
edit- ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b c d e f g h Zorec, J.; Royer, F. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789.
- ^ a b Morgan, W. W.; Keenan, P. C. (1973), "Spectral Classification", Annual Review of Astronomy and Astrophysics, 11: 29, Bibcode:1973ARA&A..11...29M, doi:10.1146/annurev.aa.11.090173.000333.
- ^ a b Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
- ^ a b c Cotten, Tara H.; Song, Inseok (July 2016), "A Comprehensive Census of Nearby Infrared Excess Stars", The Astrophysical Journal Supplement Series, 225 (1): 24, arXiv:1606.01134, Bibcode:2016ApJS..225...15C, doi:10.3847/0067-0049/225/1/15, S2CID 118438871, 15.
- ^ a b c 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, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
- ^ "18 Tau". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-20.
- ^ Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976
- ^ Eggen, Olin J. (October 1998), "The Pleiades and alpha Persei Clusters", The Astronomical Journal, 116 (4): 1810–1815, Bibcode:1998AJ....116.1810E, doi:10.1086/300533
- ^ Meyer, C.; et al. (1995), "Observations of lunar occultations at Observatoire de la Cote d'Azur", Astronomy and Astrophysics Supplement, 110: 107, Bibcode:1995A&AS..110..107M. See SAO 76137 on p. 112