111 Tauri

111 Tauri
Observation data
Epoch J2000      Equinox J2000
Constellation Taurus
Right ascension 05h 24m 25.46380s[1]
Declination +17° 23′ 00.7166″[1]
Apparent magnitude (V) 5.1149[1]
Characteristics
Spectral type F8 V + K5 V[2]
U−B color index −0.05[3]
B−V color index 0.544[1]
Variable type BY Dra[3]
Astrometry
Radial velocity (Rv)+37.8[4] km/s
Proper motion (μ) RA: +251.05[1] mas/yr
Dec.: −7.99[1] mas/yr
Parallax (π)69.51 ± 0.38[1] mas
Distance46.9 ± 0.3 ly
(14.39 ± 0.08 pc)
Absolute magnitude (MV)3.49 ± 0.06[5]
Details
111 Tau A
Mass1.08[5] M☉
Radius1.67 ± 0.06[5] R☉
Luminosity1.845[6] L☉
Surface gravity (log g)4.24[7] cgs
Temperature6,015[7] K
Metallicity [Fe/H]−0.14[7] dex
Rotation4.1 days[8]
Rotational velocity (v sin i)16.0[9] km/s
Age3.76[10] Gyr
Other designations
111 Tau, GJ 202, HR 1780, BD+17 920, HD 35296, LTT 11642, SAO 94526, HIP 25278.[3]

111 Tauri is a wide binary star[2] system in the constellation Taurus. It is located at a distance of about 47 light years from the Sun. Primary component A is a main sequence star with a stellar classification of F8V. The secondary component B (Gliese 201) is a K-type main sequence star.[2] It is larger and more luminous than the Sun, with about 130% of the Sun's radius and 185% of the Sun's luminosity. The apparent magnitude of 5.1 indicates it is a faint star that can be viewed by the naked eye under good, dark-sky conditions.

The metallicity of the primary star, which measures the proportion of elements other than hydrogen and helium, is similar to the Sun. Estimates of [Fe/H], which is the logarithm of the ratio of iron to hydrogen as compared to the Sun, range from a low of −0.14 to a high of 0.05.[7][8] This star shows an unusually high content of Lithium, which remains unexplained.[8] Age estimates for this star range from 3.6 to 3.76 billion years.[4][10] It is a prominent X-ray source.[8]

This star is rotating relatively rapidly, completing a rotation along the equator every 4.1 days as compared to 25 days for the Sun. It is also undergoing differential rotation in which the rotation velocity varies by latitude.[11]

This star was examined for an excess of infrared emission that could indicate it has a circumstellar debris disk of dust, but no significant excess was observed.[10] The space velocity components of this star are [U, V, W] = [−36.94, −14.63, 7.63] km/s.[12] It shares a common proper motion with HIP 25220, an active star with stellar classification K4V. Both stars are members of the Hyades stellar kinematic group of co-moving stars.[8]

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 van Leeuwen, F. (November 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.
  2. ↑ 2.0 2.1 2.2 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. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x.
  3. ↑ 3.0 3.1 3.2 "V* V1119 Tau -- Variable of BY Dra". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2011-07-03.
  4. ↑ 4.0 4.1 Holmberg, J.; Nordstrom, B.; Andersen, J. (July 2009). "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics". Astronomy and Astrophysics 501 (3): 941–947. arXiv:0811.3982. Bibcode:2009A&A...501..941H. doi:10.1051/0004-6361/200811191.
  5. ↑ 5.0 5.1 5.2 Fuhrmann, Klaus (February 2008), "Nearby stars of the Galactic disc and halo - IV", Monthly Notices of the Royal Astronomical Society 384 (1): 173–224, Bibcode:2008MNRAS.384..173F, doi:10.1111/j.1365-2966.2007.12671.x
  6. ↑ Takeda, Yoichi (April 2007). "Fundamental Parameters and Elemental Abundances of 160 F-G-K Stars Based on OAO Spectrum Database". Publications of the Astronomical Society of Japan 59 (2): 335–356. Bibcode:2007PASJ...59..335T. doi:10.1093/pasj/59.2.335.
  7. ↑ 7.0 7.1 7.2 7.3 Chen, Y. Q.; Nissen, P. E.; Zhao, G.; Zhang, H. W.; Benoni, T. (February 2000). "Chemical composition of 90 F and G disk dwarfs". Astronomy and Astrophysics Supplement 141: 491–506. arXiv:astro-ph/9912342. Bibcode:2000A&AS..141..491C. doi:10.1051/aas:2000124.
  8. ↑ 8.0 8.1 8.2 8.3 8.4 Makarov, V. V.; Zacharias, N.; Hennessy, G. S. (November 2008). "Common Proper Motion Companions to Nearby Stars: Ages and Evolution". The Astrophysical Journal 687 (1): 566–578. arXiv:0808.3414. Bibcode:2008ApJ...687..566M. doi:10.1086/591638.
  9. ↑ Schröder, C.; Reiners, A.; Schmitt, J. H. M. M. (January 2009). "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo". Astronomy and Astrophysics 493 (3): 1099–1107. Bibcode:2009A&A...493.1099S. doi:10.1051/0004-6361:200810377.
  10. ↑ 10.0 10.1 10.2 Trilling, D. E. et al. (February 2008). "Debris Disks around Sun-like Stars". The Astrophysical Journal 674 (2): 1086–1105. arXiv:0710.5498. Bibcode:2008ApJ...674.1086T. doi:10.1086/525514.
  11. ↑ Reiners, A. (January 2006). "Rotation- and temperature-dependence of stellar latitudinal differential rotation". Astronomy and Astrophysics 446 (1): 267–277. arXiv:astro-ph/0509399. Bibcode:2006A&A...446..267R. doi:10.1051/0004-6361:20053911.
  12. ↑ Montes, D. et al. (November 2001). "Late-type members of young stellar kinematic groups - I. Single stars". Monthly Notices of the Royal Astronomical Society 328 (1): 45–63. arXiv:astro-ph/0106537. Bibcode:2001MNRAS.328...45M. doi:10.1046/j.1365-8711.2001.04781.x.