Theta Indi

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θ Indi
Indus constellation map.svg
Red circle.svg

Location of θ Indi (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Indus
Right ascension 21h 19m 51.98955s[1]
Declination −53° 26′ 57.9315″[1]
Apparent magnitude (V) 4.40[2]
Spectral type A5IV-V[3]
B−V color index +0.18[2]
Radial velocity (Rv) -14.50[4] km/s
Proper motion (μ) RA: +107.90[1] mas/yr
Dec.: -66.41[1] mas/yr
Parallax (π) 33.02 ± 0.49[1] mas
Distance 99 ± 1 ly
(30.3 ± 0.4 pc)
Absolute magnitude (MV) 1.98[5]
Mass 1.75[6] M
Luminosity 12.95[7] L
Temperature 8,332[6] K
Other designations
GC 29819, HIP 105319, HR 8140, HD 202730, SAO 246965, WDS J21199-5327AB [2]
Database references

Theta Indi (θ Ind) is a binary star in the constellation Indus. Its apparent magnitude is 4.40[2] and it is approximately 98.8 light years away based on parallax.[1] The smaller companion, B, has a spectral type of G0V (yellow main-sequence) and an apparent magnitude of 7.18 at a separation of 6.71".[8] Recent observations suggest the primary is itself a binary with components Aa and Ab orbiting at 0.0617", estimated period about 1.3 years.[9][10]


  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:0708.1752Freely accessible. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.  Vizier catalog entry
  2. ^ a b c d "Theta Indi". SIMBAD Astronomical Database. Retrieved 2016-08-23. 
  3. ^ Gray, R. O.; Garrison, R. F. (July 1989), "The late A-type stars - Refined MK classification, confrontation with Stromgren photometry, and the effects of rotation", Astrophysical Journal Supplement Series, 70 (4): 623–636, Bibcode:1989ApJS...70..623G, doi:10.1086/191349 
  4. ^ Wilson, R. E. (1953), General Catalogue of Stellar Radial Velocities, Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W, LCCN 54001336 
  5. ^ Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971Freely accessible. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015.  Vizier catalog entry
  6. ^ a b David, Trevor J.; Hillenbrand, Lynne A. (May 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): 146–184. arXiv:1501.03154Freely accessible. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146.  Vizier catalog entry
  7. ^ McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (2012). "Fundamental parameters and infrared excesses of Hipparcos stars". Monthly Notices of the Royal Astronomical Society. 427: 343. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x.  Vizier catalog entry
  8. ^ 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:0806.2878Freely accessible, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x  Vizier catalog entry
  9. ^ Mason, Brian D.; et al. (December 2001), "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920  Vizier catalog entry
  10. ^ Marion, L.; Absil, O.; Ertel, S.; Le Bouquin, J.-B.; Defrère, D. (July 2014), "Unveiling new stellar companions from the PIONIER exozodi survey", Proceedings of the SPIE, 9146, arXiv:1410.5714Freely accessible, Bibcode:2014SPIE.9146E..1KM, doi:10.1117/12.2057823