Astronomy:Tau Sculptoris

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Short description: Star in the constellation Sculptor
Tau Sculptoris
Observation data
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[1] mas
Distance230 ± 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
Mass1.56[7] M
Surface gravity (log g)3.96±0.14[7] cgs
Temperature7,155±243[7] K
Metallicity [Fe/H]−0.12[8] dex
Rotational velocity (v sin i)73.8±7.8[9] km/s
Age1.284[7] Gyr
τ Her B
Mass1.37[6] M
Other designations
τ Scl, CD−30° 540, HD 9906, HIP 7463, HR 462, SAO 193201, WDS J01361-2954[10]
Database references
SIMBADdata

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.

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

  1. 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode1966CoLPL...4...99J. 
  3. 3.0 3.1 3.2 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, Bibcode2008MNRAS.389..869E. 
  4. 4.0 4.1 Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, 3, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode1982mcts.book.....H. 
  5. 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, Bibcode2012A&A...546A..61D. 
  6. 6.0 6.1 6.2 6.3 6.4 Cvetkovic, Z.; Novakovic, B. (December 2006), "Orbits For Sixteen Binaries", Serbian Astronomical Journal 173 (173): 73–82, doi:10.2298/SAJ0673073C, Bibcode2006SerAJ.173...73C. 
  7. 7.0 7.1 7.2 7.3 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, Bibcode2015ApJ...804..146D. 
  8. 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, doi:10.1051/0004-6361/201016276, Bibcode2011A&A...530A.138C. 
  9. 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, doi:10.1051/0004-6361/201118724, Bibcode2012A&A...542A.116A. 
  10. "tau Scl". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=tau+Scl. 
  11. O'Meara, Steve (2007), Herschel 400 Observing Guide, Cambridge University Press, p. 302, ISBN 978-0521858939, https://books.google.com/books?id=Nyh9fAC_tpIC&pg=PA302.