Theta Indi

θ Indi
	Location of θ Indi (circled)
Observation data; Epoch J2000 Equinox J2000
Constellation	Indus
Right ascension	21h 19m 51.98955s
Declination	−53° 26′ 57.9315″
Apparent magnitude (V)	4.40
Characteristics
Spectral type	A5IV-V
B−V color index	+0.18
Astrometry
Radial velocity (Rv)	−14.50 km/s
Proper motion (μ)	RA: +107.90 mas/yr ; Dec.: −66.41 mas/yr
Parallax (π)	33.02 ± 0.49 mas
Distance	99 ± 1 ly ; (30.3 ± 0.4 pc)
Absolute magnitude (MV)	1.98
Details
Mass	1.75 M☉
Radius	1.61 R☉
Luminosity	12.95 L☉
Temperature	8,332 K
Rotational velocity (v sin i)	135 km/s
Age	150±100 Myr
Other designations
	CPD−53° 10037, GC 29819, HIP 105319, HR 8140, HD 202730, SAO 246965, WDS J21199-5327AB
Database references
SIMBAD	data

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″.^[9] Recent observations suggest the primary is itself a binary with components Aa and Ab orbiting at 0.0617″, estimated period about 1.3 years.^[10]^[11]

References

^ ^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
^ ^a ^b ^c ^d "Theta Indi". SIMBAD Astronomical Database. Retrieved 2016-08-23.
^ 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
^ Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W, LCCN 54001336
^ Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644. Vizier catalog entry
^ ^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:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146. S2CID 33401607. Vizier catalog entry
^ ^a ^b ^c Plavchan, Peter; et al. (June 2009), "New Debris Disks Around Young, Low-Mass Stars Discovered with the Spitzer Space Telescope", The Astrophysical Journal, 698 (2): 1068–1094, arXiv:0904.0819, Bibcode:2009ApJ...698.1068P, doi:10.1088/0004-637X/698/2/1068, S2CID 51417657.
^ 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 (1): 343–357. arXiv:1208.2037. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x. S2CID 118665352. Vizier catalog entry
^ 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, S2CID 14878976 Vizier catalog entry
^ 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
^ Marion, L.; Absil, O.; Ertel, S.; Le Bouquin, J.-B.; Defrère, D. (July 2014), Rajagopal, Jayadev K; Creech-Eakman, Michelle J; Malbet, Fabien (eds.), "Unveiling new stellar companions from the PIONIER exozodi survey", Proceedings of the SPIE, Optical and Infrared Interferometry IV, 9146: 91461K, arXiv:1410.5714, Bibcode:2014SPIE.9146E..1KM, doi:10.1117/12.2057823, S2CID 54045048

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[vanLeeuwen2007-1] ^ ^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

[SIMBAD-2] "Theta Indi". SIMBAD Astronomical Database. Retrieved 2016-08-23.

[Gray2003-3] 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

[Wilson1953-4] Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W, LCCN 54001336

[XHIP-5] Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644. Vizier catalog entry

[David2015-6] 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:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146. S2CID 33401607. Vizier catalog entry

[Plavchan2009-7] Plavchan, Peter; et al. (June 2009), "New Debris Disks Around Young, Low-Mass Stars Discovered with the Spitzer Space Telescope", The Astrophysical Journal, 698 (2): 1068–1094, arXiv:0904.0819, Bibcode:2009ApJ...698.1068P, doi:10.1088/0004-637X/698/2/1068, S2CID 51417657.

[McDonald2012-8] 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 (1): 343–357. arXiv:1208.2037. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x. S2CID 118665352. Vizier catalog entry

[Eggleton2008-9] 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, S2CID 14878976 Vizier catalog entry

[WDS-10] 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

[Marion2014-11] Marion, L.; Absil, O.; Ertel, S.; Le Bouquin, J.-B.; Defrère, D. (July 2014), Rajagopal, Jayadev K; Creech-Eakman, Michelle J; Malbet, Fabien (eds.), "Unveiling new stellar companions from the PIONIER exozodi survey", Proceedings of the SPIE, Optical and Infrared Interferometry IV, 9146: 91461K, arXiv:1410.5714, Bibcode:2014SPIE.9146E..1KM, doi:10.1117/12.2057823, S2CID 54045048

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Observation data Epoch J2000 Equinox J2000
Location of θ Indi (circled)
Constellation	Indus
Right ascension	21^h 19^m 51.98955^s^[1]
Declination	−53° 26′ 57.9315″^[1]
Apparent magnitude (V)	4.40^[2]
Characteristics
Spectral type	A5IV-V^[3]
B−V color index	+0.18^[2]
Astrometry

Radial velocity (R_v)	−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 mas^[1]
Distance	99 ± 1 ly (30.3 ± 0.4 pc)
Absolute magnitude (M_V)	1.98^[5]

Details

Mass	1.75^[6] `M`_☉
Radius	1.61^[7] `R`_☉
Luminosity	12.95^[8] `L`_☉
Temperature	8,332^[6] K
Rotational velocity (v sin i)	135^[7] km/s
Age	150±100^[7] Myr

Other designations
CPD−53° 10037, GC 29819, HIP 105319, HR 8140, HD 202730, SAO 246965, WDS J21199-5327AB ^[2]
Database references
SIMBAD	data