36 Ophiuchi
| 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 mas[1] |
| 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 | |
| Database references | |
| SIMBAD | AB |
| A | |
| B | |
| C | |
| Exoplanet Archive | A |
| B | |
| C | |
| ARICNS | A |
| B | |
| C | |
36 Ophiuchi, formally named Guniibuu /ɡəˈniːbuː/, 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 dwarfs 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.
Nomenclature
In the Kamilaroi and Euahlayi Aboriginal peoples in modern-day New South Wales, Australia, the star A is called Guniibuu that represents the robin red-breast bird (Petroica boodang). In 2016, the IAU organized a Working Group on Star Names (WGSN)[6] to catalog and standardize proper names for stars. The WGSN approved the name Guniibuu for the star A on 10 August 2018 and it is now so included in the List of IAU-approved Star Names.[7]
Hunt for substellar objects
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.[8]
The star C (or namely HD 156026) is among five nearby paradigms as K-type stars of a type in a 'sweet spot’ between Sun-analog stars and M stars for the likelihood of evolved life, per analysis of Giada Arney from NASA’s Goddard Space Flight Center.[9]
See also
Notes
- ^ 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.
References
- ^ a b c d e f g h "SIMBAD Astronomical Database". Centre de Données astronomiques de Strasbourg. Retrieved 2013-08-23.
- ^ 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
- ^ 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
- ^ a b Wittenmeyer et al. (2006).
- ^ 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
- ^ "IAU Working Group on Star Names (WGSN)". Retrieved 17 September 2018.
- ^ "IAU Catalog of Star Names". International Astronomical Union. Retrieved 2018-09-17.
- ^ Irwin et al. (1996).
- ^
Bill Steigerwald (2019-03-07). ""Goldilocks" Stars May Be "Just Right" for Finding Habitable Worlds". NASA. Retrieved 2020-05-12.
'I find that certain nearby K stars like 61 Cyg A/B, Epsilon Indi, Groombridge 1618, and HD 156026 may be particularly good targets for future biosignature searches,' said Arney.
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Further reading
- 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
{{citation}}: Unknown parameter|lastauthoramp=ignored (|name-list-style=suggested) (help) - 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
{{citation}}: Unknown parameter|lastauthoramp=ignored (|name-list-style=suggested) (help) - 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
{{citation}}: Unknown parameter|lastauthoramp=ignored (|name-list-style=suggested) (help) - 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
- "36 Ophiuchi". SolStation. Retrieved 3 November 2005.
- https://arxiv.org/abs/astro-ph/0604171
