Iota Tauri


ι Tauri
Taurus constellation map.svg
Red circle.svg
Location of ι Tauri (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Taurus
Right ascension 05h 03m 05.74725s[1]
Declination 21° 35′ 23.8627″[1]
Apparent magnitude (V) 4.62[2]
Spectral type A7 V[3]
U−B color index +0.15[4]
B−V color index +0.16[4]
Radial velocity (Rv)+38.30[5] km/s
Proper motion (μ) RA: +68.88[1] mas/yr
Dec.: -41.06[1] mas/yr
Parallax (π)18.88 ± 0.30[1] mas
Distance173 ± 3 ly
(53.0 ± 0.8 pc)
Absolute magnitude (MV)1.00[2]
Mass2.22[6] M
Radius2.6[7] R
Luminosity36[6] L
Surface gravity (log g)3.97[8] cgs
Temperature8,054[6] K
Metallicity [Fe/H]+0.15[2] dex
Rotational velocity (v sin i)131[6] km/s
Age717[8] Myr
Other designations
ι Tau, 102 Tauri, BD+21° 751, FK5 184, GC 6158, HD 32301, HIP 23497, HR 1620, SAO 76920, WDS J05031+2135AB, GSC 01293-02747
Database references

Iota Tauri, Latinized from ι Tauri, is a white-hued star in the zodiac constellation Taurus and an outlying member of the Hyades star cluster.[9] It is visible to the naked eye with an apparent visual magnitude of 4.62,[2] and is located at an estimated distance of about 173 light years based upon parallax measurements.[1] The star is moving away from the Sun with a radial velocity of +38 km/s.[5]

This has been reported as a double star with two components at separation 0.1", both of type A7V and magnitude 5.4.[10][11] The combined spectrum matches a stellar classification of A7 V,[3] which would normally indicate an A-type main-sequence star that is generating energy through hydrogen fusion at its core. It has an estimated age of 717[8] million years.


  1. ^ 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. Vizier catalog entry
  2. ^ a b c d Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644. Vizier catalog entry
  3. ^ a b Abt, Helmut A.; Morrell, Nidia I. (1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". Astrophysical Journal Supplement. 99: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182.
  4. ^ a b Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers. 42 (2): 443. Bibcode:2014JAVSO..42..443M.Vizier catalog entry
  5. ^ a b 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.
  6. ^ a b c d Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars". Astronomy & Astrophysics. 537: A120. arXiv:1201.2052. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691. S2CID 55586789. Vizier catalog entry
  7. ^ Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555–562. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A. Vizier catalog entry
  8. ^ a b c 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. Vizier catalog entry
  9. ^ Varenne, O.; Monier, R. (November 1999), "Chemical abundances of A and F-type stars: the Hyades open cluster", Astronomy and Astrophysics, 351: 247–266, Bibcode:1999A&A...351..247V.
  10. ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. Vizier catalog entry
  11. ^ Eggleton, P. P.; Tokovinin, A. A. (2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976. Vizier catalog entry