XZ Tauri


XZ Tauri is a binary system approximately 460 light-years away in the constellation Taurus. The system consists of two T Tauri stars orbiting each other about 6 billion kilometers apart (roughly the same distance as Pluto is from the Sun). The system made news in 2000 when a superflare was observed in the system.

XZ Tauri
A visual band light curve for XZ Tauri. The main plot shows the long-term variability, and the inset shows the year 2000 superflare on the north star. Adapted from Dodin et al. (2016)[1] and Coffey et al. (2004).[2]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Taurus
Right ascension 04h 31m 40.08690s[3]
Declination +18° 13′ 56.6424″[3]
Apparent magnitude (V) 10.40[4]
Spectral type M2.0 + M3.5[5]
Proper motion (μ) RA: 9.1[6] mas/yr
Dec.: −17.8[6] mas/yr
Distance460 ly
(140[7] pc)
Period (P)155 yr
Semi-major axis (a)0.172+0.002
Eccentricity (e)0.742+0.025
Inclination (i)0.0°
Argument of periastron (ω)
Mass0.37 M
Radius1.1 R
Luminosity0.17 L
Mass0.29 M
Radius1.7 R
Luminosity0.31 L
Temperature3,550[7] K
Age4.6[7] Myr
Other designations
XZ Tau, GSC 01269-00171[9]
Database references

A third star, component C, has been observed at a separation of 0.09, but subsequent observations failed to find it.[10][8] The T Tauri star HL Tauri, 23″ away, is also sometimes listed as a companion.[9]



  1. ^ a b Sources vary on their definitions of the primary and secondary components. A is defined here as the more massive component, with a lower temperature but higher luminosity. Other sources refer to the components as north and south,[2] or Aa and Ab.[9] The southerly star Ab is generally brighter at optical wavelengths and more massive, but is less luminous.


  1. ^ Dodin, A. V.; Emelyanov, N. V.; Zharova, A. V.; Lamzin, S. A.; Malogolovets, E. V.; Roe, J. M. (January 2016). "Orbital motions and light curves of young binaries XZ Tau and VY Tau". Astronomy Letters. 42 (1): 29–40. Bibcode:2016AstL...42...29D. doi:10.1134/S1063773716010035.
  2. ^ a b Coffey, D.; Downes, T. P.; Ray, T. P. (May 2004). "The evolution and simulation of the outburst from XZ Tauri – A possible EXor?". Astronomy and Astrophysics. 419 (2): 593–598. Bibcode:2004A&A...419..593C. doi:10.1051/0004-6361:20034316.
  3. ^ a b 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.
  4. ^ Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
  5. ^ a b Hartigan, Patrick; Kenyon, Scott J. (January 2003). "A Spectroscopic Survey of Subarcsecond Binaries in the Taurus-Auriga Dark Cloud with the Hubble Space Telescope". The Astrophysical Journal. 583 (1): 334–357. arXiv:astro-ph/0209608. Bibcode:2003ApJ...583..334H. doi:10.1086/345293.
  6. ^ a b Zacharias, N. (2003). "VizieR Online Data Catalog: The Second U.S. Naval Observatory CCD Astrograph Catalog (UCAC2)". bCDS/ADC Collection of Electronic Catalogues. Bibcode:2003yCat.1289....0Z.
  7. ^ a b c Osorio, Mayra; et al. (July 2016). "A Dwarf Transitional Protoplanetary Disk around XZ Tau B". The Astrophysical Journal Letters. 825 (1): 6. arXiv:1606.03118. Bibcode:2016ApJ...825L..10O. doi:10.3847/2041-8205/825/1/L10. L10.
  8. ^ a b Ichikawa, Takanori; Kido, Miyu; Takaishi, Daisuke; Shimajiri, Yoshito; Tsukamoto, Yusuke; Takakuwa, Shigehisa (2021). "Misaligned Circumstellar Disks and Orbital Motion of the Young Binary XZ Tau". The Astrophysical Journal. 919 (1): 55. arXiv:2106.11924. Bibcode:2021ApJ...919...55I. doi:10.3847/1538-4357/ac0dc3. S2CID 235593373.
  9. ^ a b c "XZ Tau". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-12-09.
  10. ^ Osorio, Mayra; MacÍas, Enrique; Anglada, Guillem; Carrasco-González, Carlos; Galván-Madrid, Roberto; Zapata, Luis; Calvet, Nuria; Gómez, José F.; Nagel, Erick; Rodríguez, Luis F.; Torrelles, José M.; Zhu, Zhaohuan (2016). "A Dwarf Transitional Protoplanetary Disk Around Xz Tau B". The Astrophysical Journal. 825 (1): L10. arXiv:1606.03118. Bibcode:2016ApJ...825L..10O. doi:10.3847/2041-8205/825/1/L10. S2CID 59585588.
  11. ^ "Jets, bubbles, and bursts of light in Taurus". www.spacetelescope.org. ESA/Hubble. Retrieved 6 November 2014.

External linksEdit

  • "Movies from Hubble Show the Changing Faces of Infant Stars". HubbleSite. NASA. 21 September 2000. Retrieved 23 August 2009.
  • XZ Tauri at Constellation Guide