36 Ophiuchi

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36 Ophiuchi A/B/C
Observation data
Epoch J2000      Equinox J2000
Constellation Ophiuchus
Right ascension A: 17h 15m 20.851s
B: 17h 15m 20.978s
C: 17h 16m 13.3624s[1]
Declination A: −26° 36′ 09.04″
B: −26° 36′ 10.18″
C: −26° 32′ 46.129″[1]
Apparent magnitude (V) 5.08/5.08/6.34[1]
Characteristics
Spectral type K2 V/K1 V/K5 V[1]
U−B color index 0.51(AB)/1.04
B−V color index 0.86(AB)/1.15
Variable type C: RS CV
Astrometry
Radial velocity (Rv) -0.6/0.0/-1.6[1] km/s
Proper motion (μ) RA: -488.2/-473/-480.06[1] mas/yr
Dec.: -1156.0/-1143/-1123.48[1] mas/yr
Parallax (π) 167.1 ± 1.1[1] mas
Distance 19.5 ± 0.1 ly
(5.98 ± 0.04 pc)
Orbit
Companion 36 Ophiuchi B
Period (P) 568.9 yr
Semi-major axis (a) 14.7"
Eccentricity (e) 0.922
Inclination (i) 99.6°
Longitude of the node (Ω) -83.6°
Periastron epoch (T) 1763.39
Details
36 Oph A/B
Mass 0.85/0.85 M
Radius 0.817 ± 0.016[2]/0.81 R
Luminosity (bolometric) 0.33/0.36[note 1] L
Luminosity (visual, LV) 0.28/0.27 L
Temperature 4,843 ± 134[2]/4,985 ± 20[3] K
Metallicity B: –0.31 ± 0.042[3] dex
Metallicity [Fe/H] A: –0.20[2] dex
Age 0.6-1.8[4][5] Gyr
36 Oph C
Mass 0.71 M
Radius 0.72 R
Luminosity (bolometric) 0.20[note 1] L
Luminosity (visual, LV) 0.09 L
Temperature 4,550 K
Metallicity 46-100% Sun
Other designations
36 Oph, GJ 663 AB and 664, HR 6402/6401/-, CD CD-26°12026, HD 155886/155885/156026, GCTP 3908.00 AB/3913.00, LHS 437/438/439, SAO 185198/185199/185213, HIP 84405/84478.
Database references
SIMBAD data
Exoplanet Archive data
ARICNS data
Database references
SIMBAD data
Exoplanet Archive data
ARICNS data
Database references
SIMBAD data
Exoplanet Archive data
ARICNS data

36 Ophiuchi is a triple star system 19.5 light years away from Earth. It is in the constellation Ophiuchus.

The primary and secondary stars are nearly identical orange main sequence dwarves of spectral type K2/K1 and the tertiary star is an orange main sequence dwarf of spectral type K5.

Star C is separated from the A-B pair by 700 arc seconds, compared to a minimum of 4.6 arcsec for A-B, so it has a negligible effect on the movements of the A-B pair. Both A and B have active chromospheres.

Distance[edit]

36 Ophiuchi distance estimates

Source Parallax, mas Distance, pc Distance, ly Ref.
Woolley et al. (1970) (AB) 189 ± 9 5.29+0.26
−0.24
17.3+0.9
−0.8
[6]
Woolley et al. (1970) (C) 178 ± 8 5.62+0.26
−0.24
18.3+0.9
−0.8
[7]
Gliese & Jahreiß (1991) (AB) 187.6 ± 7.8 5.33+0.23
−0.21
17.4+0.8
−0.7
[8]
Gliese & Jahreiß (1991) (C) 182.0 ± 12.4 5.5 ± 0.4 17.9+1.3
−1.1
[9]
van Altena et al. (1995) (AB) 187.4 ± 9.3 5.34+0.28
−0.25
17.4+0.9
−0.8
[10]
van Altena et al. (1995) (C) 177.4 ± 9.7 5.64+0.33
−0.29
18.4+1.1
−1
[11]
Perryman et al. (1997) (Hipparcos) (AB) 167.08 ± 1.07 5.99 ± 0.04 19.52+0.13
−0.12
[12]
Perryman et al. (1997) (Hipparcos) (C) 167.56 ± 1.06 5.97 ± 0.04 19.47 ± 0.12 [13]
Perryman et al. (1997) (Tycho) (AB) (absents) [14]
Perryman et al. (1997) (Tycho) (C) (absents) [15]
van Leeuwen (2007) (AB) 168.54 ± 0.54 5.933 ± 0.019 19.35 ± 0.06 [16]
van Leeuwen (2007) (C) 167.49 ± 0.60 5.971 ± 0.021 19.47 ± 0.07 [17]
RECONS TOP100 (2012) 168.12 ± 0.40[note 2] 5.948 ± 0.014 19.4 ± 0.05 [18]

Non-trigonometric distance estimates are marked in italic. The best estimate is marked in bold.

Hunt for substellar objects[edit]

The McDonald Observatory team has set limits to the presence of one or more planets[4] around 36 Ophiuchi A with masses between 0.13 and 5.4 Jupiter masses and average separations spanning between 0.05 and 5.2 astronomical units, although beyond 1.5 AU orbits are inherently unstable around either 36 Ophiuchi A or 36 Ophiuchi B.[19]

See also[edit]

Notes[edit]

  1. ^ a b From L=4πR2σTeff4, where L is the luminosity, R is the radius, Teff is the effective surface temperature and σ is the Stefan–Boltzmann constant.
  2. ^ Weighted parallax based on parallaxes from van Altena et al. (1995) (for components AB and C) and van Leeuwen (2007) (for components AB and C).

References[edit]

  1. ^ a b c d e f g h "SIMBAD Astronomical Database". Centre de Données astronomiques de Strasbourg. Retrieved 2013-08-23. 
  2. ^ a b c Demory, B.-O. et al. (October 2009), "Mass-radius relation of low and very low-mass stars revisited with the VLTI", Astronomy and Astrophysics 505 (1): 205–215, arXiv:0906.0602, Bibcode:2009A&A...505..205D, doi:10.1051/0004-6361/200911976 
  3. ^ a b Taylor, B. J. (December 2005), "Statistical Cataloging of Archival Data for Luminosity Class IV-V Stars. III. The Epoch 2004 [Fe/H] and Temperature Catalogs", The Astrophysical Journal Supplement Series 161 (2): 444–455, Bibcode:2005ApJS..161..444T, doi:10.1086/496885. Vizier catalog entry
  4. ^ a b Wittenmeyer et al. (2006).
  5. ^ Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008), "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics", The Astrophysical Journal 687 (2): 1264–1293, arXiv:0807.1686, Bibcode:2008ApJ...687.1264M, doi:10.1086/591785 
  6. ^ Woolley R.; Epps E. A.; Penston M. J.; Pocock S. B. (1970). "Woolley 663". Catalogue of stars within 25 parsecs of the Sun. Retrieved 2014-11-21. 
  7. ^ Woolley R.; Epps E. A.; Penston M. J.; Pocock S. B. (1970). "Woolley 664". Catalogue of stars within 25 parsecs of the Sun. Retrieved 2014-11-21. 
  8. ^ Gliese, W. and Jahreiß, H. (1991). "Gl 663". Preliminary Version of the Third Catalogue of Nearby Stars. Retrieved 2014-11-21. 
  9. ^ Gliese, W. and Jahreiß, H. (1991). "Gl 664". Preliminary Version of the Third Catalogue of Nearby Stars. Retrieved 2014-11-21. 
  10. ^ Van Altena W. F., Lee J. T., Hoffleit E. D. (1995). "GCTP 3908". The General Catalogue of Trigonometric Stellar Parallaxes, Fourth Edition. Retrieved 2014-11-21. 
  11. ^ Van Altena W. F., Lee J. T., Hoffleit E. D. (1995). "GCTP 3913". The General Catalogue of Trigonometric Stellar Parallaxes, Fourth Edition. Retrieved 2014-11-21. 
  12. ^ Perryman et al. (1997). "HIP 84405". The Hipparcos and Tycho Catalogues. Retrieved 2014-11-21. 
  13. ^ Perryman et al. (1997). "HIP 84478". The Hipparcos and Tycho Catalogues. Retrieved 2014-11-21. 
  14. ^ Perryman et al. (1997). "HIP 84405". The Hipparcos and Tycho Catalogues. Retrieved 2014-11-21. 
  15. ^ Perryman et al. (1997). "HIP 84478". The Hipparcos and Tycho Catalogues. Retrieved 2014-11-21. 
  16. ^ van Leeuwen F. (2007). "HIP 84405". Validation of the new Hipparcos reduction. Retrieved 2014-11-21. 
  17. ^ van Leeuwen F. (2007). "HIP 84478". Validation of the new Hipparcos reduction. Retrieved 2014-11-21. 
  18. ^ "RECONS TOP100". THE ONE HUNDRED NEAREST STAR SYSTEMS brought to you by RECONS (Research Consortium On Nearby Stars). 2012. Retrieved 2014-11-21. 
  19. ^ Irwin et al. (1996).

Further reading[edit]

  • Irwin, Alan W.; Yang, Stephenson L. S. & Walker, Gordon A. H. (1996), "36 Ophiuchi AB: Incompatibility of the Orbit and Precise Radial Velocities", Publications of the Astronomical Society of the Pacific 108: 580, Bibcode:1996PASP..108..580I, doi:10.1086/133768 
  • Cayrel de Strobel, G.; Lebreton, Y.; Perrin, M.-N. & Cayrel, R. (1989), "A thorough spectroscopic study of the very nearby triple system - 36 Ophiuchi", Astronomy and Astrophysics 225 (2): 369–380, Bibcode:1989A&A...225..369C 
  • Wittenmeyer, R. A.; Endl, Michael; Cochran, William D.; Hatzes, Artie P.; Walker, G. A. H.; Yang, S. L. S. & Paulson, Diane B. (2006), "Detection Limits from the McDonald Observatory Planet Search Program", Astronomical Journal 132 (1): 177–188, arXiv:astro-ph/0604171, Bibcode:2006AJ....132..177W, doi:10.1086/504942 
  • Barnes, Sydney A. (2007), "Ages for Illustrative Field Stars Using Gyrochronology: Viability, Limitations, and Errors", The Astrophysical Journal 669 (2): 1167–1189, arXiv:0704.3068, Bibcode:2007ApJ...669.1167B, doi:10.1086/519295 

External links[edit]