Article · Wikipedia archive · Last revised Jun 20, 2026

UX Tauri

UX Tauri, abbreviated as UX Tau, is a binary star system approximately 450 light-years away in the constellation of Taurus. It is notable for the fact that, despite its recent creation, the Spitzer Space Telescope discovered that its protoplanetary disk contains a gap. The dust, which normally accumulates in an expanding ring starting right next to the star at such a young age, is either very thin or nonexistent at a range of 0.2 to 56 AU from the star. Typically, this means that the early ancestors of planets may be forming from the disk, though the star only ignited about 1 million years ago. In contrast, Earth was formed approximately 4.54 billion years ago, placing its formation about sixty million years after the Sun's ignition around 4.6 billion years ago.

Last revised
Jun 20, 2026
Read time
≈ 3 min
Length
661 w
Citations
31
Source
Wikipedia ↗
UX Tauri

An artist's conception of a circumstellar disk around UX Tauri A, along with several hypothetical protoplanets
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Taurus1
Right ascension 04h 30m 03.99626s2
Declination +18° 13′ 49.4355″2
Apparent magnitude (V) 10.5 - 13.93
Characteristics
Spectral type K2Ve + M1Ve4
Variable type T Tau5
Astrometry
Radial velocity (Rv)22.906 km/s
Proper motion (μ) RA: 17.18 mas/yr2
Dec.: -21.91 mas/yr2
Parallax (π)-3.70±5.73 mas2
Distance454.7 ± 6.5 ly
(139.4±2.07 pc)
Details
UX Tauri A
Mass2.34+0.29
−0.437 M☉
Radius3.37a R☉
Luminosity8.9+3.7
−2.57 L☉
Surface gravity (log g)3.77±0.177 cgs
Temperature5,490+130
−2107 K
Metallicity [Fe/H]+0.02±0.027 dex
Rotation5.0±0.97 days
Rotational velocity (v sin i)128±127 km/s
Age1.26+1.03
−0.637 Myr
UX Tauri B
Mass0.48 M☉
Radius1.98b R☉
Luminosity0.58 L☉
Surface gravity (log g)3.58 cgs
Temperature3,5008 K
Age18 Myr
Other designations
UX Tau, HD 285846, HIP 20990, WDS J04301+1814AB, CCDM J04301+1814AB, 1RXS J043004.5+1813429
Database references
SIMBADdata
A visual-band light curve for UX Tauri, plotted from ASAS-SN data10 source ↗

UX Tauri, abbreviated as UX Tau, is a binary star system approximately 450 light-years away in the constellation of Taurus (the Bull). It is notable for the fact that, despite its recent (in stellar terms) creation, the Spitzer Space Telescope discovered that its protoplanetary disk contains a gap. The dust, which normally accumulates in an expanding ring starting right next to the star at such a young age, is either very thin or nonexistent at a range of 0.2 to 56 AU from the star. Typically, this means that the early ancestors of planets may be forming from the disk, though the star only ignited about 1 million years ago.11 In contrast, Earth was formed approximately 4.54 billion years ago, placing its formation about sixty million years after the Sun's ignition around 4.6 billion years ago.

See also

See also

Notes

Notes

  1. Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5,772 K: ( 5 , 772 5 , 490 ) 4 ⋅ 10 0.95 = 3.3   R ⊙ . {\displaystyle {\sqrt {{\biggl (}{\frac {5,772}{5,490}}{\biggr )}^{4}\cdot 10^{0.95}}}=3.3\ R_{\odot }.}
  2. Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5,772 K: ( 5 , 772 3 , 500 ) 4 ⋅ 0.5 = 1.9   R ⊙ . {\displaystyle {\sqrt {{\biggl (}{\frac {5,772}{3,500}}{\biggr )}^{4}\cdot 0.5}}=1.9\ R_{\odot }.}
References

References

  1. Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
  2. 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. Vizier catalog entry Archived 2019-04-02 at the Wayback Machine
  3. "UX Tau". International Variable Star Index. Retrieved 2025-04-30.
  4. Herbig, G. H. (1977). "Radial velocities and spectral types of T Tauri stars". Astrophysical Journal. 214: 747–758. Bibcode:1977ApJ...214..747H. doi:10.1086/155304.
  5. Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085.
  6. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 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.
  7. Mendigutía, I.; Campbell-White, J.; Montesinos, B.; Maldonado, J.; Fullana-García, L.; Mirouh, G. M.; Meeus, G.; Vioque, M.; Sicilia-Aguilar, A.; Zapatero-Osorio, M. R.; Villaver, E.; Kahar, R. (2026-04-06). "Lithium and the evolution of intermediate-mass T Tauri and Herbig stars. Rotation, accretion, and planets". Astronomy & Astrophysics. arXiv:2604.05040. doi:10.1051/0004-6361/202659302. ISSN 0004-6361.
  8. Magazzu, A. (1991). "Lithium in the pre-main sequence triple system UX Tauri". Astronomy and Astrophysics. 249 (1): 149–155. Bibcode:1991A&A...249..149M.
  9. "UX Tau". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 5 December 2016.
  10. "ASAS-SN Variable Stars Database". ASAS-SN Variable Stars Database. ASAS-SN. Retrieved 6 January 2022.
  11. "NASA - Youthful Star Sprouts Planets Early". Archived from the original on 2012-10-21. Retrieved 2007-11-28.
External links
  • Magazzu, A.; Martin, E. L.; Rebolo, R. (September 1991). "Lithium in the pre-main sequence triple system UX Tauri". Astronomy and Astrophysics. 249 (1): 149. Bibcode:1991A&A...249..149M.
  • "UX Tauri". Jumk.de. Retrieved 2008-06-16.