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 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; 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 its effect on the movements of the A-B pair is small. A and B have active chromospheres.

Distance[edit]

36 Ophiuchi distance estimates

Source Parallax, mas Distance, pc Distance, ly Distance, Pm Ref.
Woolley et al. (1970) (AB) 189±9 5.29+0.26
−0.24
17.3+0.9
−0.8
163.3+8.2
−7.4
[6]
Woolley et al. (1970) (C) 178±8 5.62+0.26
−0.24
18.3+0.9
−0.8
173.4+8.2
−7.5
[7]
Gliese & Jahreiß (1991) (AB) 187.6±7.8 5.33+0.23
−0.21
17.4+0.8
−0.7
164.5+7.1
−6.6
[8]
Gliese & Jahreiß (1991) (C) 182.0±12.4 5.5±0.4 17.9+1.3
−1.1
169.5+12.4
−10.8
[9]
van Altena et al. (1995) (AB) 187.4±9.3 5.34+0.28
−0.25
17.4+0.9
−0.8
164.7+8.6
−7.8
[10]
van Altena et al. (1995) (C) 177.4±9.7 5.64+0.33
−0.29
18.4+1.1
−1
173.9+10.1
−9
[11]
Perryman et al. (1997) (Hipparcos) (AB) 167.08±1.07 5.99±0.04 19.52+0.13
−0.12
184.7±1.2 [12]
Perryman et al. (1997) (Hipparcos) (C) 167.56±1.06 5.97±0.04 19.47±0.12 184.2±1.2 [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±0.06 183.1±0.6 [16]
van Leeuwen (2007) (C) 167.49±0.60 5.971±0.021 19.47±0.07 184.2±0.7 [17]
RECONS TOP100 (2012) 168.12±0.40[note 2] 5.948±0.014 19.4±0.05 183.5±0.4 [18]

Non-trigonometric distance estimates are marked in italic. The most precise 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 ed.). 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 ed.). 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]