Tau Sculptoris (τ Scl, τ Sculptoris) is a binary star[6] system in the southern constellation of Sculptor, about 8° to the east-southeast of Alpha Sculptoris.[11] It is faintly visible to the naked eye with a combined apparent visual magnitude of +5.69.[2] Based upon an annual parallax shift of 14.42 mas as seen from Earth,[1] it is located around 230 light years from the Sun.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Sculptor |
| Right ascension | 01h 36m 08.50799s[1] |
| Declination | −29° 54′ 26.3540″[1] |
| Apparent magnitude (V) | +5.69[2] (6.06 + 7.35)[3] |
| Characteristics | |
| Spectral type | F2 V[4] |
| B−V color index | +0.33[2] |
| Astrometry | |
| Radial velocity (Rv) | +3.00±4.50[5] km/s |
| Proper motion (μ) | RA: +117.37[1] mas/yr Dec.: +46.72[1] mas/yr |
| Parallax (π) | 14.42 ± 0.81 mas[1] |
| Distance | 230 ± 10 ly (69 ± 4 pc) |
| Absolute magnitude (MV) | 2.04 + 3.02[6] |
| Orbit[6] | |
| Period (P) | 1503.58 ± 35.32 yr |
| Semi-major axis (a) | 3.155±0.132″ |
| Eccentricity (e) | 0.604±0.019 |
| Inclination (i) | 55.6±0.8° |
| Longitude of the node (Ω) | 69.6±0.8° |
| Periastron epoch (T) | 2039.79 ± 33.80 |
| Argument of periastron (ω) (secondary) | 140.2±2.8° |
| Details | |
| τ Her A | |
| Mass | 1.56[7] M☉ |
| Surface gravity (log g) | 3.96±0.14[7] cgs |
| Temperature | 7,155±243[7] K |
| Metallicity [Fe/H] | −0.12[8] dex |
| Rotational velocity (v sin i) | 73.8±7.8[9] km/s |
| Age | 1.284[7] Gyr |
| τ Her B | |
| Mass | 1.37[6] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
The binary nature of this system was discovered by English astronomer John Herschel in 1835. The current orbital elements are based upon a fraction of a single orbit, as the estimated orbital period is around 1,503 years. The system has a semimajor axis of 3.2 arc seconds and an eccentricity of 0.6.[6] The primary member, component A, is a yellow-white hued F-type main sequence star with an apparent magnitude of +6.06[3] and a stellar classification of F2 V.[4] The companion, component B, is a magnitude 7.35 star.[3]
References
edit- ^ a b c d e f van Leeuwen, F. (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.
- ^ a b c 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.
- ^ a b c 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ a b Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 3, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
- ^ 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, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
- ^ a b c d e Cvetkovic, Z.; Novakovic, B. (December 2006), "Orbits For Sixteen Binaries", Serbian Astronomical Journal, 173 (173): 73–82, Bibcode:2006SerAJ.173...73C, doi:10.2298/SAJ0673073C.
- ^ a b c d 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.
- ^ Casagrande, L.; et al. (2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy & Astrophysics, 530 (A138): 21, arXiv:1103.4651, Bibcode:2011A&A...530A.138C, doi:10.1051/0004-6361/201016276, S2CID 56118016.
- ^ Ammler-von Eiff, Matthias; Reiners, Ansgar (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics, 542: A116, arXiv:1204.2459, Bibcode:2012A&A...542A.116A, doi:10.1051/0004-6361/201118724, S2CID 53666672.
- ^ "tau Scl". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-04-11.
{{cite web}}: CS1 maint: postscript (link) - ^ O'Meara, Steve (2007), Herschel 400 Observing Guide, Cambridge University Press, p. 302, ISBN 978-0521858939.